[转]关于fragment

版权声明：本文为博主原创文章，未经博主允许不得转载。

目录(?)[+]

1. Fragment的产生与介绍
2. Fragment的生命周期
3. 静态的使用Fragment
4. 动态的使用Fragment
5. Fragment家族常用的API
6.

转载请标明出处：http://blog.csdn.net/lmj623565791/article/details/37970961



自从Fragment出现，曾经有段时间，感觉大家谈什么都能跟Fragment谈上关系，做什么都要问下Fragment能实现不

本篇博客力求为大家说明Fragment如何产生，什么是Fragment，Fragment生命周期，如何静态和动态的使用Fragment，Fragment回退栈，Fragment事务；以及Fragment的一些特殊用途，例如：没有布局的Fragment有何用处？Fragment如何与Activity交互？Fragment如何创建对话框？Fragment如何与ActionBar集成等等。

## ## ##  <a></a><span>1、Fragment的产生与介绍</span>

<span></span>Android运行在各种各样的设备中，有小屏幕的手机，超大屏的平板甚至电视。针对屏幕尺寸的差距，很多情况下，都是先针对手机开发一套App，然后拷贝一份，修改布局以适应平板神马超级大屏的。难道无法做到一个App可以同时适应手机和平板么，当然了，必须有啊。Fragment的出现就是为了解决这样的问题。你可以把Fragment当成Activity的一个界面的一个组成部分，甚至Activity的界面可以完全有不同的Fragment组成，更帅气的是Fragment拥有自己的生命周期和接收、处理用户的事件，这样就不必在Activity写一堆控件的事件处理的代码了。更为重要的是，你可以动态的添加、替换和移除某个Fragment。

## ## ##  <a></a><span>2、Fragment的生命周期</span>

<span></span>Fragment必须是依存与Activity而存在的，因此Activity的生命周期会直接影响到Fragment的生命周期。官网这张图很好的说明了两者生命周期的关系：

![](http://img.blog.csdn.net/20140719225005356?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvbG1qNjIzNTY1Nzkx/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

可以看到Fragment比Activity多了几个额外的生命周期回调方法：
**onAttach(Activity)**
<span></span><span></span>当Fragment与Activity发生关联时调用。
**onCreateView(LayoutInflater, ViewGroup,Bundle)**
<span></span><span></span>创建该Fragment的视图
**onActivityCreated(Bundle)**
<span></span><span></span>当Activity的onCreate方法返回时调用
**onDestoryView()**
<span></span><span></span>与onCreateView想对应，当该Fragment的视图被移除时调用
**onDetach()**
<span></span><span></span>与onAttach相对应，当Fragment与Activity关联被取消时调用
注意：除了onCreateView，其他的所有方法如果你重写了，必须调用父类对于该方法的实现，

## ## ##  <a></a><span>3、静态的使用Fragment</span>

嘿嘿，终于到使用的时刻了~~

这是使用Fragment最简单的一种方式，把Fragment当成普通的控件，直接写在Activity的布局文件中。步骤：

**1、继承Fragment，重写onCreateView决定Fragemnt的布局**

**2、在Activity中声明此Fragment，就当和普通的View一样**

下面展示一个例子（我使用2个Fragment作为Activity的布局，一个Fragment用于标题布局，一个Fragment用于内容布局）：

TitleFragment的布局文件:
<div class="dp-highlighter bg_html"><div class="bar"><div class="tools">**[html]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="tag">&lt;?</span><span class="tag-name">xml</span><span>&nbsp;</span><span class="attribute">version</span><span>=</span><span class="attribute-value">“1.0”</span><span>&nbsp;</span><span class="attribute">encoding</span><span>=</span><span class="attribute-value">“utf-8”</span><span class="tag">?&gt;</span><span>&nbsp;&nbsp;</span></span>
2.  <span><span class="tag">&lt;</span><span class="tag-name">RelativeLayout</span><span>&nbsp;</span><span class="attribute">xmlns:android</span><span>=</span><span class="attribute-value">“http://schemas.android.com/apk/res/android”</span><span>&nbsp;&nbsp;</span></span>
3.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“match_parent”</span><span>&nbsp;&nbsp;</span></span>
4.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“45dp”</span><span>&nbsp;&nbsp;</span></span>
5.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:background</span><span>=</span><span class="attribute-value">“@drawable/title_bar”</span><span>&nbsp;</span><span class="tag">&gt;</span><span>&nbsp;&nbsp;</span></span>
6.  <span>&nbsp;&nbsp;</span>
7.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span class="tag-name">ImageButton</span><span>&nbsp;&nbsp;</span></span>
8.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:id</span><span>=</span><span class="attribute-value">“@+id/id_title_left_btn”</span><span>&nbsp;&nbsp;</span></span>
9.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“wrap_content”</span><span>&nbsp;&nbsp;</span></span>
10.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“wrap_content”</span><span>&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_centerVertical</span><span>=</span><span class="attribute-value">“true”</span><span>&nbsp;&nbsp;</span></span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_marginLeft</span><span>=</span><span class="attribute-value">“3dp”</span><span>&nbsp;&nbsp;</span></span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:background</span><span>=</span><span class="attribute-value">“@drawable/showleft_selector”</span><span>&nbsp;</span><span class="tag">/&gt;</span><span>&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;</span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span class="tag-name">TextView</span><span>&nbsp;&nbsp;</span></span>
16.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
18.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:gravity</span><span>=</span><span class="attribute-value">“center”</span><span>&nbsp;&nbsp;</span></span>
19.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:text</span><span>=</span><span class="attribute-value">“我不是微信”</span><span>&nbsp;&nbsp;</span></span>
20.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:textColor</span><span>=</span><span class="attribute-value">“# fff”</span><span>&nbsp;&nbsp;</span></span>
21.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:textSize</span><span>=</span><span class="attribute-value">“20sp”</span><span>&nbsp;&nbsp;</span></span>
22.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:textStyle</span><span>=</span><span class="attribute-value">“bold”</span><span>&nbsp;</span><span class="tag">/&gt;</span><span>&nbsp;&nbsp;</span></span>
23.  <span>&nbsp;&nbsp;</span>
24.  <span><span class="tag">&lt;/</span><span class="tag-name">RelativeLayout</span><span class="tag">&gt;</span><span>&nbsp;&nbsp;</span></span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="html">&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="45dp"
    android:background="@drawable/title_bar" &gt;

    &lt;ImageButton
        android:id="@+id/id_title_left_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="3dp"
        android:background="@drawable/showleft_selector" /&gt;

    &lt;TextView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:text="我不是微信"
        android:textColor="# fff"
        android:textSize="20sp"
        android:textStyle="bold" /&gt;

&lt;/RelativeLayout&gt;</pre>
TitleFragment<div class="dp-highlighter bg_java"><div class="bar"><div class="tools">**[java]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="keyword">package</span><span>&nbsp;com.zhy.zhy_fragments;&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;</span>
3.  <span><span class="keyword">import</span><span>&nbsp;android.app.Fragment;&nbsp;&nbsp;</span></span>
4.  <span><span class="keyword">import</span><span>&nbsp;android.os.Bundle;&nbsp;&nbsp;</span></span>
5.  <span><span class="keyword">import</span><span>&nbsp;android.view.LayoutInflater;&nbsp;&nbsp;</span></span>
6.  <span><span class="keyword">import</span><span>&nbsp;android.view.View;&nbsp;&nbsp;</span></span>
7.  <span><span class="keyword">import</span><span>&nbsp;android.view.View.OnClickListener;&nbsp;&nbsp;</span></span>
8.  <span><span class="keyword">import</span><span>&nbsp;android.view.ViewGroup;&nbsp;&nbsp;</span></span>
9.  <span><span class="keyword">import</span><span>&nbsp;android.widget.ImageButton;&nbsp;&nbsp;</span></span>
10.  <span><span class="keyword">import</span><span>&nbsp;android.widget.Toast;&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;</span>
12.  <span><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;TitleFragment&nbsp;</span><span class="keyword">extends</span><span>&nbsp;Fragment&nbsp;&nbsp;</span></span>
13.  <span>{&nbsp;&nbsp;</span>
14.  <span>&nbsp;&nbsp;</span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">private</span><span>&nbsp;ImageButton&nbsp;mLeftMenu;&nbsp;&nbsp;</span></span>
16.  <span>&nbsp;&nbsp;</span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
18.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;View&nbsp;onCreateView(LayoutInflater&nbsp;inflater,&nbsp;ViewGroup&nbsp;container,&nbsp;&nbsp;</span></span>
19.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Bundle&nbsp;savedInstanceState)&nbsp;&nbsp;</span>
20.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
21.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;View&nbsp;view&nbsp;=&nbsp;inflater.inflate(R.layout.fragment_title,&nbsp;container,&nbsp;<span class="keyword">false</span><span>);&nbsp;&nbsp;</span></span>
22.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mLeftMenu&nbsp;=&nbsp;(ImageButton)&nbsp;view.findViewById(R.id.id_title_left_btn);&nbsp;&nbsp;</span>
23.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mLeftMenu.setOnClickListener(<span class="keyword">new</span><span>&nbsp;OnClickListener()&nbsp;&nbsp;</span></span>
24.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
25.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
26.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onClick(View&nbsp;v)&nbsp;&nbsp;</span></span>
27.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
28.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Toast.makeText(getActivity(),&nbsp;&nbsp;</span>
29.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="string">”i&nbsp;am&nbsp;an&nbsp;ImageButton&nbsp;in&nbsp;TitleFragment&nbsp;!&nbsp;”</span><span>,&nbsp;&nbsp;</span></span>
30.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Toast.LENGTH_SHORT).show();&nbsp;&nbsp;</span>
31.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
32.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;});&nbsp;&nbsp;</span>
33.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">return</span><span>&nbsp;view;&nbsp;&nbsp;</span></span>
34.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
35.  <span>}&nbsp;&nbsp;</span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="java">package com.zhy.zhy_fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.Toast;

public class TitleFragment extends Fragment
{

    private ImageButton mLeftMenu;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        View view = inflater.inflate(R.layout.fragment_title, container, false);
        mLeftMenu = (ImageButton) view.findViewById(R.id.id_title_left_btn);
        mLeftMenu.setOnClickListener(new OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                Toast.makeText(getActivity(),
                        "i am an ImageButton in TitleFragment ! ",
                        Toast.LENGTH_SHORT).show();
            }
        });
        return view;
    }
}
</pre>
同理还有ContentFragment的其布局文件：<div class="dp-highlighter bg_html"><div class="bar"><div class="tools">**[html]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="tag">&lt;?</span><span class="tag-name">xml</span><span>&nbsp;</span><span class="attribute">version</span><span>=</span><span class="attribute-value">“1.0”</span><span>&nbsp;</span><span class="attribute">encoding</span><span>=</span><span class="attribute-value">“utf-8”</span><span class="tag">?&gt;</span><span>&nbsp;&nbsp;</span></span>
2.  <span><span class="tag">&lt;</span><span class="tag-name">LinearLayout</span><span>&nbsp;</span><span class="attribute">xmlns:android</span><span>=</span><span class="attribute-value">“http://schemas.android.com/apk/res/android”</span><span>&nbsp;&nbsp;</span></span>
3.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“match_parent”</span><span>&nbsp;&nbsp;</span></span>
4.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“match_parent”</span><span>&nbsp;&nbsp;</span></span>
5.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:orientation</span><span>=</span><span class="attribute-value">“vertical”</span><span>&nbsp;</span><span class="tag">&gt;</span><span>&nbsp;&nbsp;</span></span>
6.  <span>&nbsp;&nbsp;</span>
7.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span class="tag-name">TextView</span><span>&nbsp;&nbsp;</span></span>
8.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
9.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
10.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:gravity</span><span>=</span><span class="attribute-value">“center”</span><span>&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:text</span><span>=</span><span class="attribute-value">“使用Fragment做主面板”</span><span>&nbsp;&nbsp;</span></span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:textSize</span><span>=</span><span class="attribute-value">“20sp”</span><span>&nbsp;&nbsp;</span></span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:textStyle</span><span>=</span><span class="attribute-value">“bold”</span><span>&nbsp;</span><span class="tag">/&gt;</span><span>&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;</span>
15.  <span><span class="tag">&lt;/</span><span class="tag-name">LinearLayout</span><span class="tag">&gt;</span><span>&nbsp;&nbsp;</span></span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="html">&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" &gt;

    &lt;TextView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:text="使用Fragment做主面板"
        android:textSize="20sp"
        android:textStyle="bold" /&gt;

&lt;/LinearLayout&gt;</pre>
<div class="dp-highlighter bg_java"><div class="bar"><div class="tools">**[java]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="keyword">package</span><span>&nbsp;com.zhy.zhy_fragments;&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;</span>
3.  <span><span class="keyword">import</span><span>&nbsp;android.app.Fragment;&nbsp;&nbsp;</span></span>
4.  <span><span class="keyword">import</span><span>&nbsp;android.os.Bundle;&nbsp;&nbsp;</span></span>
5.  <span><span class="keyword">import</span><span>&nbsp;android.view.LayoutInflater;&nbsp;&nbsp;</span></span>
6.  <span><span class="keyword">import</span><span>&nbsp;android.view.View;&nbsp;&nbsp;</span></span>
7.  <span><span class="keyword">import</span><span>&nbsp;android.view.ViewGroup;&nbsp;&nbsp;</span></span>
8.  <span>&nbsp;&nbsp;</span>
9.  <span><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;ContentFragment&nbsp;</span><span class="keyword">extends</span><span>&nbsp;Fragment&nbsp;&nbsp;</span></span>
10.  <span>{&nbsp;&nbsp;</span>
11.  <span>&nbsp;&nbsp;</span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;View&nbsp;onCreateView(LayoutInflater&nbsp;inflater,&nbsp;ViewGroup&nbsp;container,&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Bundle&nbsp;savedInstanceState)&nbsp;&nbsp;</span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
16.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">return</span><span>&nbsp;inflater.inflate(R.layout.fragment_content,&nbsp;container,&nbsp;</span><span class="keyword">false</span><span>);&nbsp;&nbsp;</span></span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
18.  <span>&nbsp;&nbsp;</span>
19.  <span>}&nbsp;&nbsp;</span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="java">package com.zhy.zhy_fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class ContentFragment extends Fragment
{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        return inflater.inflate(R.layout.fragment_content, container, false);
    }

}
</pre>
MainActivity<div class="dp-highlighter bg_java"><div class="bar"><div class="tools">**[java]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="keyword">package</span><span>&nbsp;com.zhy.zhy_fragments;&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;</span>
3.  <span><span class="keyword">import</span><span>&nbsp;android.app.Activity;&nbsp;&nbsp;</span></span>
4.  <span><span class="keyword">import</span><span>&nbsp;android.os.Bundle;&nbsp;&nbsp;</span></span>
5.  <span><span class="keyword">import</span><span>&nbsp;android.view.Window;&nbsp;&nbsp;</span></span>
6.  <span>&nbsp;&nbsp;</span>
7.  <span><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;MainActivity&nbsp;</span><span class="keyword">extends</span><span>&nbsp;Activity&nbsp;&nbsp;</span></span>
8.  <span>{&nbsp;&nbsp;</span>
9.  <span>&nbsp;&nbsp;</span>
10.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">protected</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onCreate(Bundle&nbsp;savedInstanceState)&nbsp;&nbsp;</span></span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">super</span><span>.onCreate(savedInstanceState);&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;requestWindowFeature(Window.FEATURE_NO_TITLE);&nbsp;&nbsp;</span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;setContentView(R.layout.activity_main);&nbsp;&nbsp;</span>
16.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
17.  <span>&nbsp;&nbsp;</span>
18.  <span>}&nbsp;&nbsp;</span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="java">package com.zhy.zhy_fragments;

import android.app.Activity;
import android.os.Bundle;
import android.view.Window;

public class MainActivity extends Activity
{

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
    }

}
</pre>
Activity的布局文件：<div class="dp-highlighter bg_java"><div class="bar"><div class="tools">**[java]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span>&lt;RelativeLayout&nbsp;xmlns:android=</span><span class="string">“http://schemas.android.com/apk/res/android”</span><span>&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;&nbsp;&nbsp;xmlns:tools=<span class="string">”http://schemas.android.com/tools”</span><span>&nbsp;&nbsp;</span></span>
3.  <span>&nbsp;&nbsp;&nbsp;&nbsp;android:layout_width=<span class="string">”match_parent”</span><span>&nbsp;&nbsp;</span></span>
4.  <span>&nbsp;&nbsp;&nbsp;&nbsp;android:layout_height=<span class="string">”match_parent”</span><span>&nbsp;&gt;&nbsp;&nbsp;</span></span>
5.  <span>&nbsp;&nbsp;</span>
6.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&lt;fragment&nbsp;&nbsp;</span>
7.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:id=<span class="string">”@+id/id_fragment_title”</span><span>&nbsp;&nbsp;</span></span>
8.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:name=<span class="string">”com.zhy.zhy_fragments.TitleFragment”</span><span>&nbsp;&nbsp;</span></span>
9.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:layout_width=<span class="string">”fill_parent”</span><span>&nbsp;&nbsp;</span></span>
10.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:layout_height=<span class="string">”45dp”</span><span>&nbsp;/&gt;&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;</span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&lt;fragment&nbsp;&nbsp;</span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:layout_below=<span class="string">”@id/id_fragment_title”</span><span>&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:id=<span class="string">”@+id/id_fragment_content”</span><span>&nbsp;&nbsp;</span></span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:name=<span class="string">”com.zhy.zhy_fragments.ContentFragment”</span><span>&nbsp;&nbsp;</span></span>
16.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:layout_width=<span class="string">”fill_parent”</span><span>&nbsp;&nbsp;</span></span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;android:layout_height=<span class="string">”fill_parent”</span><span>&nbsp;/&gt;&nbsp;&nbsp;</span></span>
18.  <span>&nbsp;&nbsp;</span>
19.  <span>&lt;/RelativeLayout&gt;&nbsp;&nbsp;</span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="java">&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" &gt;

    &lt;fragment
        android:id="@+id/id_fragment_title"
        android:name="com.zhy.zhy_fragments.TitleFragment"
        android:layout_width="fill_parent"
        android:layout_height="45dp" /&gt;

    &lt;fragment
        android:layout_below="@id/id_fragment_title"
        android:id="@+id/id_fragment_content"
        android:name="com.zhy.zhy_fragments.ContentFragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" /&gt;

&lt;/RelativeLayout&gt;</pre>
是不是把Fragment当成普通的View一样声明在Activity的布局文件中，然后所有控件的事件处理等代码都由各自的Fragment去处理，瞬间觉得Activity好干净有木有~~代码的可读性、复用性以及可维护性是不是瞬间提升了~~~下面看下效果图：

![](http://img.blog.csdn.net/20140719230904593)

## ## ##  <a></a><span>4、动态的使用Fragment</span>

上面已经演示了，最简单的使用Fragment的方式~下面介绍如何动态的添加、更新、以及删除Fragment

为了动态使用Fragment，我们修改一下Actvity的布局文件，中间使用一个FrameLayout，下面添加四个按钮~~~嘿嘿~~不是微信的按钮- -！
<div class="dp-highlighter bg_html"><div class="bar"><div class="tools">**[html]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="tag">&lt;</span><span class="tag-name">RelativeLayout</span><span>&nbsp;</span><span class="attribute">xmlns:android</span><span>=</span><span class="attribute-value">“http://schemas.android.com/apk/res/android”</span><span>&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">xmlns:tools</span><span>=</span><span class="attribute-value">“http://schemas.android.com/tools”</span><span>&nbsp;&nbsp;</span></span>
3.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“match_parent”</span><span>&nbsp;&nbsp;</span></span>
4.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“match_parent”</span><span>&nbsp;</span><span class="tag">&gt;</span><span>&nbsp;&nbsp;</span></span>
5.  <span>&nbsp;&nbsp;</span>
6.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span class="tag-name">fragment</span><span>&nbsp;&nbsp;</span></span>
7.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:id</span><span>=</span><span class="attribute-value">“@+id/id_fragment_title”</span><span>&nbsp;&nbsp;</span></span>
8.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:name</span><span>=</span><span class="attribute-value">“com.zhy.zhy_fragments.TitleFragment”</span><span>&nbsp;&nbsp;</span></span>
9.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
10.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“45dp”</span><span>&nbsp;</span><span class="tag">/&gt;</span><span>&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;</span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span class="tag-name">include</span><span>&nbsp;&nbsp;</span></span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:id</span><span>=</span><span class="attribute-value">“@+id/id_ly_bottombar”</span><span>&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“55dp”</span><span>&nbsp;&nbsp;</span></span>
16.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_alignParentBottom</span><span>=</span><span class="attribute-value">“true”</span><span>&nbsp;&nbsp;</span></span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">layout</span><span>=</span><span class="attribute-value">“@layout/bottombar”</span><span>&nbsp;</span><span class="tag">/&gt;</span><span>&nbsp;&nbsp;</span></span>
18.  <span>&nbsp;&nbsp;</span>
19.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span class="tag-name">FrameLayout</span><span>&nbsp;&nbsp;</span></span>
20.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:id</span><span>=</span><span class="attribute-value">“@+id/id_content”</span><span>&nbsp;&nbsp;</span></span>
21.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_width</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
22.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_height</span><span>=</span><span class="attribute-value">“fill_parent”</span><span>&nbsp;&nbsp;</span></span>
23.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_above</span><span>=</span><span class="attribute-value">“@id/id_ly_bottombar”</span><span>&nbsp;&nbsp;</span></span>
24.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">android:layout_below</span><span>=</span><span class="attribute-value">“@id/id_fragment_title”</span><span>&nbsp;</span><span class="tag">/&gt;</span><span>&nbsp;&nbsp;</span></span>
25.  <span>&nbsp;&nbsp;</span>
26.  <span><span class="tag">&lt;/</span><span class="tag-name">RelativeLayout</span><span class="tag">&gt;</span><span>&nbsp;&nbsp;</span></span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="html">&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" &gt;

    &lt;fragment
        android:id="@+id/id_fragment_title"
        android:name="com.zhy.zhy_fragments.TitleFragment"
        android:layout_width="fill_parent"
        android:layout_height="45dp" /&gt;

    &lt;include
        android:id="@+id/id_ly_bottombar"
        android:layout_width="fill_parent"
        android:layout_height="55dp"
        android:layout_alignParentBottom="true"
        layout="@layout/bottombar" /&gt;

    &lt;FrameLayout
        android:id="@+id/id_content"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_above="@id/id_ly_bottombar"
        android:layout_below="@id/id_fragment_title" /&gt;

&lt;/RelativeLayout&gt;</pre>
底部四个按钮的布局就不贴了，到时看效果图就明白了~~

下面主Activity
<div class="dp-highlighter bg_java"><div class="bar"><div class="tools">**[java]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="keyword">package</span><span>&nbsp;com.zhy.zhy_fragments;&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;</span>
3.  <span><span class="keyword">import</span><span>&nbsp;android.app.Activity;&nbsp;&nbsp;</span></span>
4.  <span><span class="keyword">import</span><span>&nbsp;android.app.FragmentManager;&nbsp;&nbsp;</span></span>
5.  <span><span class="keyword">import</span><span>&nbsp;android.app.FragmentTransaction;&nbsp;&nbsp;</span></span>
6.  <span><span class="keyword">import</span><span>&nbsp;android.os.Bundle;&nbsp;&nbsp;</span></span>
7.  <span><span class="keyword">import</span><span>&nbsp;android.view.View;&nbsp;&nbsp;</span></span>
8.  <span><span class="keyword">import</span><span>&nbsp;android.view.View.OnClickListener;&nbsp;&nbsp;</span></span>
9.  <span><span class="keyword">import</span><span>&nbsp;android.view.Window;&nbsp;&nbsp;</span></span>
10.  <span><span class="keyword">import</span><span>&nbsp;android.widget.LinearLayout;&nbsp;&nbsp;</span></span>
11.  <span>&nbsp;&nbsp;</span>
12.  <span><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;MainActivity&nbsp;</span><span class="keyword">extends</span><span>&nbsp;Activity&nbsp;</span><span class="keyword">implements</span><span>&nbsp;OnClickListener&nbsp;&nbsp;</span></span>
13.  <span>{&nbsp;&nbsp;</span>
14.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">private</span><span>&nbsp;LinearLayout&nbsp;mTabWeixin;&nbsp;&nbsp;</span></span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">private</span><span>&nbsp;LinearLayout&nbsp;mTabFriend;&nbsp;&nbsp;</span></span>
16.  <span>&nbsp;&nbsp;</span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">private</span><span>&nbsp;ContentFragment&nbsp;mWeixin;&nbsp;&nbsp;</span></span>
18.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">private</span><span>&nbsp;FriendFragment&nbsp;mFriend;&nbsp;&nbsp;</span></span>
19.  <span>&nbsp;&nbsp;</span>
20.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
21.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">protected</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onCreate(Bundle&nbsp;savedInstanceState)&nbsp;&nbsp;</span></span>
22.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
23.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">super</span><span>.onCreate(savedInstanceState);&nbsp;&nbsp;</span></span>
24.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;requestWindowFeature(Window.FEATURE_NO_TITLE);&nbsp;&nbsp;</span>
25.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;setContentView(R.layout.activity_main);&nbsp;&nbsp;</span>
26.  <span>&nbsp;&nbsp;</span>
27.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;初始化控件和声明事件</span><span>&nbsp;&nbsp;</span></span>
28.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mTabWeixin&nbsp;=&nbsp;(LinearLayout)&nbsp;findViewById(R.id.tab_bottom_weixin);&nbsp;&nbsp;</span>
29.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mTabFriend&nbsp;=&nbsp;(LinearLayout)&nbsp;findViewById(R.id.tab_bottom_friend);&nbsp;&nbsp;</span>
30.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mTabWeixin.setOnClickListener(<span class="keyword">this</span><span>);&nbsp;&nbsp;</span></span>
31.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mTabFriend.setOnClickListener(<span class="keyword">this</span><span>);&nbsp;&nbsp;</span></span>
32.  <span>&nbsp;&nbsp;</span>
33.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;设置默认的Fragment</span><span>&nbsp;&nbsp;</span></span>
34.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;setDefaultFragment();&nbsp;&nbsp;</span>
35.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
36.  <span>&nbsp;&nbsp;</span>
37.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">private</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;setDefaultFragment()&nbsp;&nbsp;</span></span>
38.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
39.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;FragmentManager&nbsp;fm&nbsp;=&nbsp;getFragmentManager();&nbsp;&nbsp;</span>
40.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;FragmentTransaction&nbsp;transaction&nbsp;=&nbsp;fm.beginTransaction();&nbsp;&nbsp;</span>
41.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mWeixin&nbsp;=&nbsp;<span class="keyword">new</span><span>&nbsp;ContentFragment();&nbsp;&nbsp;</span></span>
42.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;transaction.replace(R.id.id_content,&nbsp;mWeixin);&nbsp;&nbsp;</span>
43.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;transaction.commit();&nbsp;&nbsp;</span>
44.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
45.  <span>&nbsp;&nbsp;</span>
46.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
47.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onClick(View&nbsp;v)&nbsp;&nbsp;</span></span>
48.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
49.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;FragmentManager&nbsp;fm&nbsp;=&nbsp;getFragmentManager();&nbsp;&nbsp;</span>
50.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;开启Fragment事务</span><span>&nbsp;&nbsp;</span></span>
51.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;FragmentTransaction&nbsp;transaction&nbsp;=&nbsp;fm.beginTransaction();&nbsp;&nbsp;</span>
52.  <span>&nbsp;&nbsp;</span>
53.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">switch</span><span>&nbsp;(v.getId())&nbsp;&nbsp;</span></span>
54.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
55.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">case</span><span>&nbsp;R.id.tab_bottom_weixin:&nbsp;&nbsp;</span></span>
56.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">if</span><span>&nbsp;(mWeixin&nbsp;==&nbsp;</span><span class="keyword">null</span><span>)&nbsp;&nbsp;</span></span>
57.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
58.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mWeixin&nbsp;=&nbsp;<span class="keyword">new</span><span>&nbsp;ContentFragment();&nbsp;&nbsp;</span></span>
59.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
60.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;使用当前Fragment的布局替代id_content的控件</span><span>&nbsp;&nbsp;</span></span>
61.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;transaction.replace(R.id.id_content,&nbsp;mWeixin);&nbsp;&nbsp;</span>
62.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">break</span><span>;&nbsp;&nbsp;</span></span>
63.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">case</span><span>&nbsp;R.id.tab_bottom_friend:&nbsp;&nbsp;</span></span>
64.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">if</span><span>&nbsp;(mFriend&nbsp;==&nbsp;</span><span class="keyword">null</span><span>)&nbsp;&nbsp;</span></span>
65.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
66.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mFriend&nbsp;=&nbsp;<span class="keyword">new</span><span>&nbsp;FriendFragment();&nbsp;&nbsp;</span></span>
67.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
68.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;transaction.replace(R.id.id_content,&nbsp;mFriend);&nbsp;&nbsp;</span>
69.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">break</span><span>;&nbsp;&nbsp;</span></span>
70.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
71.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;transaction.addToBackStack();</span><span>&nbsp;&nbsp;</span></span>
72.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;事务提交</span><span>&nbsp;&nbsp;</span></span>
73.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;transaction.commit();&nbsp;&nbsp;</span>
74.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
75.  <span>&nbsp;&nbsp;</span>
76.  <span>}&nbsp;&nbsp;</span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="java">package com.zhy.zhy_fragments;

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.LinearLayout;

public class MainActivity extends Activity implements OnClickListener
{
    private LinearLayout mTabWeixin;
    private LinearLayout mTabFriend;

    private ContentFragment mWeixin;
    private FriendFragment mFriend;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        // 初始化控件和声明事件
        mTabWeixin = (LinearLayout) findViewById(R.id.tab_bottom_weixin);
        mTabFriend = (LinearLayout) findViewById(R.id.tab_bottom_friend);
        mTabWeixin.setOnClickListener(this);
        mTabFriend.setOnClickListener(this);

        // 设置默认的Fragment
        setDefaultFragment();
    }

    private void setDefaultFragment()
    {
        FragmentManager fm = getFragmentManager();
        FragmentTransaction transaction = fm.beginTransaction();
        mWeixin = new ContentFragment();
        transaction.replace(R.id.id_content, mWeixin);
        transaction.commit();
    }

    @Override
    public void onClick(View v)
    {
        FragmentManager fm = getFragmentManager();
        // 开启Fragment事务
        FragmentTransaction transaction = fm.beginTransaction();

        switch (v.getId())
        {
        case R.id.tab_bottom_weixin:
            if (mWeixin == null)
            {
                mWeixin = new ContentFragment();
            }
            // 使用当前Fragment的布局替代id_content的控件
            transaction.replace(R.id.id_content, mWeixin);
            break;
        case R.id.tab_bottom_friend:
            if (mFriend == null)
            {
                mFriend = new FriendFragment();
            }
            transaction.replace(R.id.id_content, mFriend);
            break;
        }
        // transaction.addToBackStack();
        // 事务提交
        transaction.commit();
    }

}
</pre>
可以看到我们使用FragmentManager对Fragment进行了动态的加载，这里使用的是replace方法~~下一节我会详细介绍FragmentManager的常用API。

注：如果使用Android3.0以下的版本，需要引入v4的包，然后Activity继承FragmentActivity，然后通过getSupportFragmentManager获得FragmentManager。不过还是建议版Menifest文件的uses-sdk的minSdkVersion和targetSdkVersion都改为11以上，这样就不必引入v4包了。

代码中间还有两个Fragment的子类，ContentFragment上面已经见过，FriendFragment其实类似：
<div class="dp-highlighter bg_java"><div class="bar"><div class="tools">**[java]** [view plain](#  "view plain")<span> [copy](#  "copy")</span><div></div><span> [print](#  "print")</span>[?](#  "?")</div></div>

1.  <span><span class="keyword">package</span><span>&nbsp;com.zhy.zhy_fragments;&nbsp;&nbsp;</span></span>
2.  <span>&nbsp;&nbsp;</span>
3.  <span><span class="keyword">import</span><span>&nbsp;android.app.Fragment;&nbsp;&nbsp;</span></span>
4.  <span><span class="keyword">import</span><span>&nbsp;android.os.Bundle;&nbsp;&nbsp;</span></span>
5.  <span><span class="keyword">import</span><span>&nbsp;android.view.LayoutInflater;&nbsp;&nbsp;</span></span>
6.  <span><span class="keyword">import</span><span>&nbsp;android.view.View;&nbsp;&nbsp;</span></span>
7.  <span><span class="keyword">import</span><span>&nbsp;android.view.ViewGroup;&nbsp;&nbsp;</span></span>
8.  <span>&nbsp;&nbsp;</span>
9.  <span><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;FriendFragment&nbsp;</span><span class="keyword">extends</span><span>&nbsp;Fragment&nbsp;&nbsp;</span></span>
10.  <span>{&nbsp;&nbsp;</span>
11.  <span>&nbsp;&nbsp;</span>
12.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="annotation">@Override</span><span>&nbsp;&nbsp;</span></span>
13.  <span>&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;View&nbsp;onCreateView(LayoutInflater&nbsp;inflater,&nbsp;ViewGroup&nbsp;container,&nbsp;&nbsp;</span></span>
14.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Bundle&nbsp;savedInstanceState)&nbsp;&nbsp;</span>
15.  <span>&nbsp;&nbsp;&nbsp;&nbsp;{&nbsp;&nbsp;</span>
16.  <span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">return</span><span>&nbsp;inflater.inflate(R.layout.fragment_friend,&nbsp;container,&nbsp;</span><span class="keyword">false</span><span>);&nbsp;&nbsp;</span></span>
17.  <span>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;</span>
18.  <span>&nbsp;&nbsp;</span>
19.  <span>}&nbsp;&nbsp;</span><div class="save_code tracking-ad"><a>![](http://static.blog.csdn.net/images/save_snippets.png)</a></div></div><pre class="java">package com.zhy.zhy_fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class FriendFragment extends Fragment
{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        return inflater.inflate(R.layout.fragment_friend, container, false);
    }

}
</pre>
效果图：

![](http://img.blog.csdn.net/20140720002532641)

可以看到很好的实现了效果，其实这个效果以前的博客中也出现过，在博客：[Android项目Tab类型主界面大总结 Fragment+TabPageIndicator+ViewPager](http://blog.csdn.net/lmj623565791/article/details/24740977)，有兴趣可以看看。ps:为了代码的简洁，就不添加按钮的点击变化什么的了，主要讲解功能了

## ## ## 5、Fragment家族常用的API

Fragment常用的三个类：

android.app.Fragment 主要用于定义Fragment

android.app.FragmentManager 主要用于在Activity中操作Fragment

android.app.FragmentTransaction 保证一些列Fragment操作的原子性，熟悉事务这个词，一定能明白~

a、获取FragmentManage的方式：

getFragmentManager() // v4中，getSupportFragmentManager

b、主要的操作都是FragmentTransaction的方法

FragmentTransaction transaction = fm.benginTransatcion();//开启一个事务

transaction.add() 

往Activity中添加一个Fragment

transaction.remove()

从Activity中移除一个Fragment，如果被移除的Fragment没有添加到回退栈（回退栈后面会详细说），这个Fragment实例将会被销毁。

transaction.replace()

使用另一个Fragment替换当前的，实际上就是remove()然后add()的合体~

transaction.hide()

隐藏当前的Fragment，仅仅是设为不可见，并不会销毁

transaction.show()

显示之前隐藏的Fragment

detach()

会将view从UI中移除,和remove()不同,此时fragment的状态依然由FragmentManager维护。

attach()

重建view视图，附加到UI上并显示。

transatcion.commit()//提交一个事务

注意：常用Fragment的哥们，可能会经常遇到这样Activity状态不一致：State loss这样的错误。主要是因为：commit方法一定要在Activity.onSaveInstance()之前调用。

上述，基本是操作Fragment的所有的方式了，在一个事务开启到提交可以进行多个的添加、移除、替换等操作。

值得注意的是：如果你喜欢使用Fragment，一定要清楚这些方法，哪个会销毁视图，哪个会销毁实例，哪个仅仅只是隐藏，这样才能更好的使用它们。

a、比如：我在FragmentA中的EditText填了一些数据，当切换到FragmentB时，如果希望会到A还能看到数据，则适合你的就是hide和show；也就是说，希望保留用户操作的面板，你可以使用hide和show，当然了不要使劲在那new实例，进行下非null判断。

b、再比如：我不希望保留用户操作，你可以使用remove()，然后add()；或者使用replace()这个和remove,add是相同的效果。

c、remove和detach有一点细微的区别，在不考虑回退栈的情况下，remove会销毁整个Fragment实例，而detach则只是销毁其视图结构，实例并不会被销毁。那么二者怎么取舍使用呢？如果你的当前Activity一直存在，那么在不希望保留用户操作的时候，你可以优先使用detach。

上述已经介绍完成了Fragment常用的一些方法，相信看完，大家一定清楚了Fragment的产生理由，以及如何使用Fragment，再根据API的讲解，也能明白，曾经为何觉得Fragment会出现一些列乱七八槽的问题，终究是因为没有弄清楚其生命周期。

由于篇幅原因，剩下的内容留到下一篇了。在下一篇，会介绍：

1、如何管理Fragment回退栈

2、Fragment如何与Activity交互

3、Fragment与Activity交互的最佳实践

4、没有视图的Fragment的用处

5、使用Fragment创建对话框

6、如何与ActionBar，MenuItem集成等~~

下一篇：Android Fragment 真正的完全解析（下）

好了，有任何问题请留言~~

会将view从UI中移除,和remove()不同,此时fragment的状态依然由FragmentManager维护。



## #

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    作者：qq_23974175 发表于2016/9/12 12:21:06 [原文链接](http://blog.csdn.net/qq_23974175/article/details/52512409)
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