Android Fragment基础及使用

同一个app内的界面切换 用Fragment比较合适，因为Activity比较重量级

Fragment 轻量级，切换灵活

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1. 创建和使用 Fragment

2. Fragment 的生命周期 及相关的实际应用

3. 创建一个带侧边栏的 Activity 以及使用

4. 创建一个 Tabbed Activity 并使用

5. 多个Fragment的切换和状态保存

6. Fragment的横竖屏切换

7. Fragment 与 Activity通信

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工程代码：FragmentDemo.zip

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1. 创建和使用 Fragment

     * 创建一个 带Fragment的Activity，将Fragment重构到一个新文件中PlaceholderFragment.java

     * 创建另一个Fragment，AnotherFragment.java

     * 使用按钮实现两个Fragment的切换

1.1 在layout fragment_main中添加一个按钮btnOpenAnohterFragment， 用于打开另一个Fragment；

    replace, add, hide, show

public class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container,
                false);
        rootView.findViewById(R.id.btnOpenAnohterFragment).setOnClickListener(
                new OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        // TODO Auto-generated method stub
                        getFragmentManager().beginTransaction()
                                .addToBackStack(null) //支持返回键,否则点返回直接退出app
                                .replace(R.id.container, new AnotherFragment())
                                .commit();
                    }
                });
        return rootView;
    }
}

1.2 在AnotherFragment 添加按钮btnBack，用于返回上一个Fragment

public class AnotherFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        View root = inflater.inflate(R.layout.fragment_another, container, false);
        
        root.findViewById(R.id.btnBack).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                getFragmentManager().popBackStack();
            }
        });
        return root; //super.onCreateView(inflater, container, savedInstanceState);
    }
}

2. Fragment 的生命周期 及相关的实际应用

比Activity的生命周期多很多，

onCreate，onCreateView，onPause是最常用的

    创建两个Fragment， A， B

        1. 打开FragmentA -> 暂停FragmentA -> 恢复FragmentA  -> 关闭FragmentA，生命周期变化如下

打开Fragment A
08-13 19:18:32.062 D 27014  27014  FragmentA:  onAttach 
08-13 19:18:32.062 D 27014  27014  FragmentA:  onCreate 
08-13 19:18:32.062 D 27014  27014  FragmentA:  onCreateView 
08-13 19:18:32.062 D 27014  27014  FragmentA:  onActivityCreated 
08-13 19:18:32.062 D 27014  27014  FragmentA:  onStart 
08-13 19:18:32.062 D 27014  27014  FragmentA:  onResume 

A Fragment 活动

暂停 Fragment A
08-13 19:19:32.352 D 27014  27014  FragmentA:  onPause 
08-13 19:19:32.382 D 27014  27014  FragmentA:  onStop 

恢复Fragment A
08-13 19:20:11.102 D 27014  27014  FragmentA:  onStart 
08-13 19:20:11.102 D 27014  27014  FragmentA:  onResume 

退出 Fragment A
08-13 19:20:52.022 D 27014  27014  FragmentA:  onPause 
08-13 19:20:52.472 D 27014  27014  FragmentA:  onStop 
08-13 19:20:52.472 D 27014  27014  FragmentA:  onDestroyView 
08-13 19:20:52.472 D 27014  27014  FragmentA:  onDestroy 
08-13 19:20:52.472 D 27014  27014  FragmentA:  onDetach 

        2. 打开FragmentA -> 由FragmentA打开FragmentB  -> 从FragmentB返回FragmentA，生命周期变化如下

打开Fragment A                  
08-13 19:51:09.227 D 5395  5395  FragmentA: onAttach 
08-13 19:51:09.227 D 5395  5395  FragmentA: onCreate 
08-13 19:51:09.237 D 5395  5395  FragmentA: onCreateView 
08-13 19:51:09.237 D 5395  5395  FragmentA: onActivityCreated 
08-13 19:51:09.237 D 5395  5395  FragmentA: onStart 
08-13 19:51:09.237 D 5395  5395  FragmentA: onResume 

从A 打开 B
08-13 19:51:12.097 D 5395  5395  FragmentA: onPause 
08-13 19:51:12.097 D 5395  5395  FragmentA: onStop 
08-13 19:51:12.097 D 5395  5395  FragmentA: onDestroyView 
FragmentA内部的View组件完成
08-13 19:51:12.097 D 5395  5395  FragmentB: onAttach 
08-13 19:51:12.097 D 5395  5395  FragmentB: onCreate 
08-13 19:51:12.097 D 5395  5395  FragmentB: onCreateView 
08-13 19:51:12.107 D 5395  5395  FragmentB: onActivityCreated 
08-13 19:51:12.107 D 5395  5395  FragmentB: onStart 
08-13 19:51:12.107 D 5395  5395  FragmentB: onResume 
B处于稳定状态
从B返回A
08-13 19:51:36.067 D 5395  5395  FragmentB: onPause 
08-13 19:51:36.067 D 5395  5395  FragmentB: onStop 
08-13 19:51:36.067 D 5395  5395  FragmentB: onDestroyView 
08-13 19:51:36.067 D 5395  5395  FragmentB: onDestroy 
08-13 19:51:36.067 D 5395  5395  FragmentB: onDetach 
08-13 19:51:36.077 D 5395  5395  FragmentA: onCreateView 
08-13 19:51:36.077 D 5395  5395  FragmentA: onActivityCreated 
08-13 19:51:36.077 D 5395  5395  FragmentA: onStart 
08-13 19:51:36.077 D 5395  5395  FragmentA: onResume 

        可以看到，两个Fragment使用replace方法切换的时候，是A完全销毁以后，才加载的B

3. 创建一个带侧边栏的 Activity 以及使用

    新建 SliderActivity： 类型Navigation Drawer Activity， 可以看到SDK默认创建了几个文件

SliderActivity.java
NavigationDrawerFragment.java

activity_slider.xml
fragment_navigation_drawer.xml
fragment_slider.xml

    * 默认效果： onCreateView中有一个ListView，来显示数据

        在 NavigationDrawerFragment.java 中 修改onCreateView 中的Adapter，添加  "CARLOZ LIB"

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    mDrawerListView = (ListView) inflater.inflate(
            R.layout.fragment_navigation_drawer, container, false);
    mDrawerListView
            .setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {
                    selectItem(position);
                }
            });
    mDrawerListView.setAdapter(new ArrayAdapter<String>(getActionBar()
            .getThemedContext(),
            android.R.layout.simple_list_item_activated_1,
            android.R.id.text1, new String[] {
                    getString(R.string.title_section1),
                    getString(R.string.title_section2),
                    getString(R.string.title_section3),
                    "CARLOZ LIB",}));
    mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
    return mDrawerListView;
}

        在 SliderActivity.java 中修改 onSectionAttached 中的添加case语句，即可出现如下效果

public void onSectionAttached(int number) {
    switch (number) {
    case 1:
        mTitle = getString(R.string.title_section1);
        break;
    case 2:
        mTitle = getString(R.string.title_section2);
        break;
    case 3:
        mTitle = getString(R.string.title_section3);
        break;
    case 4:
        mTitle = "CARLOZ LIB";
        break;
    }
}

   

    * 自定义侧边栏

      创建一个Fragment：CarlozLibFragment.java，并为其创建一个布局carloz_lib_webview.xml，内部有一个WebView控件，顺便在AndroidManifest.xml中添加Intent访问权限；在CarlozLibFragment中重写onCreateView方法，让WebView访问我的个人网站（http://carloz.duapp.com）；

public class CarlozLibFragment extends Fragment {
    private String TAG = "CARLOZ";

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        View root = inflater.inflate(R.layout.carloz_lib_webview, container, false);
        
        WebView wv =(WebView)root.findViewById(R.id.wv);
        Log.d(TAG, "load url: carloz lib");
        wv.loadUrl("http://carloz.duapp.com");
        
        return root;
    }
}

      将NavigationDrawerFragment.java 中 onCreateView中ListView相关内容删除，用自定义布局 diy_slider_content.xml （目录res/layout）替换；diy_slider_content中定义了一个按钮，用来打开刚刚创建的CarlozLibFragment；

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View root = inflater.inflate(R.layout.diy_slider_content, container, false);
    
    root.findViewById(R.id.btnJump).setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mDrawerLayout != null) {
                // 隐藏侧边栏
                mDrawerLayout.closeDrawer(mFragmentContainerView);
            }
            if(mCallbacks != null) {
                mCallbacks.onGotoCarlozLibClicked();
            }
        }
    });
    
    return root;
}

      onGotoCarlozLibClicked()这个接口是自定义接口，在 静态接口 NavigationDrawerCallbacks 中新增定义

public static interface NavigationDrawerCallbacks {
    /**
     * Called when an item in the navigation drawer is selected.
     */
    void onNavigationDrawerItemSelected(int position);
    
    // 通过回调传给主界面
    void onGotoCarlozLibClicked();
}

    需要在主界面SliderActivity中实现该回调方法， 因为主界面实现了 NavigationDrawerFragment.NavigationDrawerCallbacks 接口

@Override
public void onGotoCarlozLibClicked() {
    // 需要实现 NavigationDrawerFragment.java Callback中新增的方法
    // 在容器 container 中添加 fragment CarlozLibFragment
    getSupportFragmentManager().beginTransaction()
            .replace(R.id.container, new CarlozLibFragment())
            .commit();
}

运行结果如下：

4. 创建一个 Tabbed Activity 并使用

 默认样式：

自定义：

    * 创建drawble目录，并在里面放三张图片img1, img2, img3；

    * 创建三个ImageFragment， 分别加载三种图片

    * 在 TabsActivity 中调用三个Fragment

public class Image1Fragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        ImageView iv = new ImageView(getActivity()); 
        iv.setImageResource(R.drawable.img1);
        return iv;
    }
}

public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class
        // below).
        switch(position) {
        case 0:
            return new Image1Fragment();
        case 1:
            return new Image2Fragment();
        case 2:
            return new Image3Fragment();
        }
        
        return null;
        //return PlaceholderFragment.newInstance(position + 1);
    }

结果如下

5. 多个Fragment的切换和状态保存

    Fragment的操作有 add， replace， remove三个方法

    从2可以看出，使用replace方法来切换Fragment时会完全销毁上一个Fragment，这样再切换回上一个Fragment时，它的状态就会丢失；

    5.1 现在 有一个问题，当一个Activity中 使用了 多个同级Fragment，那么多个Fragment切换时如何保存Fragment的状态？

    智慧的网友们给出了解决方案：把用到的Fragment全部使用add方法添加， 使用hide、show方法来控制，需要使用哪个，就显示哪个。缺点是：几个Fragment会一直占用内存，直到Fragment销毁

    定义一个Activity：FragmentSwitchActivity，用于存放Fragment

    定义两个Fragment：PlaceholderFragment 和 FragmentSwitch1，用于演示 切换操作

    定义一个Callback：FragmentSwitchCallBack，用于管理Fragment 和 切换逻辑

    使用这个Callback，控制再多的Fragment都行，这里为了简单，只控制两个

public interface FragmentSwitchCallBack {
    //使用一个List管理当前添加的Fragment
    public void addFragment(String tag);
    public void removeFragment(String tag);
    public void openFragmentByTag(String tag);
}

Callback在Fragment中使用如下：

public class FragmentSwitchX extends Fragment {
    public static String TAG = "FragmentSwitch1";
    private FragmentSwitchCallBack mSwitchCallBack;

    @Override
    public void onAttach(Activity activity) {
        // TODO Auto-generated method stub
        super.onAttach(activity);
        Log.d(TAG, "onAttach");
        mSwitchCallBack = (FragmentSwitchCallBack) activity;
        mSwitchCallBack.addFragment(TAG);
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        View root = inflater.inflate(R.layout.fragment_switch1, container, false);
        
        root.findViewById(R.id.btnSwitchToPlaceholderFragment).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if(null != mSwitchCallBack){
                    Log.d(TAG, "switch to PlaceholderFragment");
                    mSwitchCallBack.openFragmentByTag(PlaceholderFragment.TAG);
                }
            }
        });
        Log.d(TAG, "onCreateView");
        return root;
    }

    @Override
    public void onDetach() {
        // TODO Auto-generated method stub
        Log.d(TAG, "onDetach");
        mSwitchCallBack.removeFragment(TAG);
        super.onDetach();
    }
}

在Activity中实现该CallBack，用来管理 Fragment List， 将需要的Fragment显示，不需要的隐藏：

public class FragmentSwitchActivity extends FragmentActivity implements
        FragmentSwitchCallBack {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment_switch);
        if (savedInstanceState == null) {
            getSupportFragmentManager()
                    .beginTransaction()
                    .add(R.id.container, new PlaceholderFragment(),
                            PlaceholderFragment.TAG).commit();
        }
    }

    private List<String> fragmnetList;
    @Override
    public void openFragmentByTag(String tag) {
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        if(null == ft) return;
        if (null == fragmnetList)
            fragmnetList = new ArrayList<String>();

        if (fragmnetList.contains(tag)) {
            for (String s : fragmnetList) {
                if (s == tag)
                    ft.show(fm.findFragmentByTag(s));
                else
                    ft.hide(fm.findFragmentByTag(s));
            }
        } else {
            if (PlaceholderFragment.TAG == tag) {
                ft.add(R.id.container, new PlaceholderFragment(), tag);
            } else if (FragmentSwitch1.TAG == tag) {
                ft.add(R.id.container, new FragmentSwitch1(), tag);
            }
            for (String s : fragmnetList) {
                ft.hide(fm.findFragmentByTag(s));
            }
        }
        ft.commit();
    }
    @Override
    public void addFragment(String tag) {
        if (null == fragmnetList)
            fragmnetList = new ArrayList<String>();
        fragmnetList.add(tag);
    }
    @Override
    public void removeFragment(String tag) {
        if (null != fragmnetList) {
            fragmnetList.remove(tag);
        }
    }
}

        两个Fragment切换时的生命周期如下

打开FragmentSwitchActivity，顺便添加第FragmentPlaceholder
08-14 16:30:43.601 D 5967     5967     FragmentPlaceholder:   onAttach 
08-14 16:30:43.601 D 5967     5967     FragmentPlaceholder:   onCreate 
08-14 16:30:43.701 D 5967     5967     FragmentPlaceholder:   onCreateView 
打开FragmentSwitch1
08-14 16:30:49.101 D 5967     5967     FragmentSwitch1:       onAttach 
08-14 16:30:49.101 D 5967     5967     FragmentSwitch1:       onCreate 
08-14 16:30:49.161 D 5967     5967     FragmentSwitch1:       onCreateView 
以后再切换，生命周期不再变化

    5.2 二级Fragment的状态保存

       此问题以后再分析~

6. 单个Fragment的横竖屏切换及状态保存

6.1 横竖屏切换时的Fragment生命周期变化如下， 会先销毁，再重新创建

08-13 20:13:59.127 D 7089 7089  FragmentA: onPause 
08-13 20:13:59.127 D 7089 7089  FragmentA: onStop 
08-13 20:13:59.127 D 7089 7089  FragmentA: onDestroyView 
08-13 20:13:59.127 D 7089 7089  FragmentA: onDestroy 
08-13 20:13:59.127 D 7089 7089  FragmentA: onDetach 

08-13 20:13:59.177 D 7089 7089  FragmentA: onAttach 
08-13 20:13:59.177 D 7089 7089  FragmentA: onCreate 
08-13 20:13:59.197 D 7089 7089  FragmentA: onCreateView 
08-13 20:13:59.197 D 7089 7089  FragmentA: onActivityCreated 
08-13 20:13:59.197 D 7089 7089  FragmentA: onStart 
08-13 20:13:59.207 D 7089 7089  FragmentA: onResume 

 6.2 默认情况下横竖屏切换后整个FragmentActivity会被销毁并重建，所有Fragment中的成员变量也会丢失，但所有的Fragment状态数据如上所述会被保留并还原，这个时候所有的视图都会重新创建。

未采取任何解决方案时的转屏log

08-14 10:17:07.389 D 6620  6620     ScreenRotationActivity:           onCreate 
08-14 10:17:07.389 D 6620  6620     ScreenRotationActivity-Fragment:  onCreate 
08-14 10:17:07.389 D 6620  6620     ScreenRotationActivity-Fragment:  onCreateView 
开始转屏
08-14 10:17:13.259 D 6620  6620     ScreenRotationActivity-Fragment:  onDestroyView 
08-14 10:17:13.259 D 6620  6620     ScreenRotationActivity-Fragment:  onDetach 

08-14 10:17:13.319 D 6620  6620     ScreenRotationActivity-Fragment:  onCreate 
08-14 10:17:13.339 D 6620  6620     ScreenRotationActivity:           onCreate 
08-14 10:17:13.349 D 6620  6620     ScreenRotationActivity-Fragment:  onCreateView 
转屏完成

6.2.1 解决方法一：在相应的Activity配置中加上android:configChanges="orientation|screenSize"设置，这样切换时就不会销毁FragmentActivity,所有的Fragment的状态及视图也就会保持。

<activity
    android:name=".v6_1.ScreenRotationActivity"
    android:configChanges="orientation|screenSize"
    android:label="@string/title_activity_screen_rotation" >
</activity>

@Override
public void onConfigurationChanged(Configuration newConfig) {
    // TODO Auto-generated method stub
    super.onConfigurationChanged(newConfig);
    Log.d(TAG, "onConfigurationChanged");
}

使用解决方案一以后的生命周期变化如下，可以解决问题：

08-14 10:21:22.429 D 7697  7697  ScreenRotationActivity:           onCreate 
08-14 10:21:22.429 D 7697  7697  ScreenRotationActivity-Fragment:  onCreate 
08-14 10:21:22.429 D 7697  7697  ScreenRotationActivity-Fragment:  onCreateView 
开始转屏
08-14 10:21:26.249 D 7697  7697  ScreenRotationActivity:           onConfigurationChanged 
转屏完成

6.2.2 解决方法二：在使用FragmentTransaction.add()方法添加fragment时设置第三个tag参数,随后在还原时可通过FragmentManager.findFragmentByTag()方法找回还原的fragment.

Fragment f = getFragmentManager().findFragmentByTag(FragmentA);
if(null == f) {
    Log.d(TAG, "onCreate: new FragmentA");
    f = new PlaceholderFragment();
}
if (savedInstanceState == null) {
    getFragmentManager().beginTransaction()
            .add(R.id.container, f, FragmentA)
            .commit();
}

    经我实验，Fragment虽然找回来了，但是还是回执行onCreateView方法，UI组件状态已丢失，哪位大神有好的方法，请@我， 简略版生命周期如下

08-14 11:01:43.639 D 10628    10628    ScreenRotationActivity:           onCreate 
08-14 11:01:43.649 D 10628    10628    ScreenRotationActivity:           onCreate: new FragmentA 
08-14 11:01:43.659 D 10628    10628    ScreenRotationActivity-Fragment:  onCreate 
08-14 11:01:43.659 D 10628    10628    ScreenRotationActivity-Fragment:  onCreateView 
开始转屏
08-14 11:01:48.129 D 10628    10628    ScreenRotationActivity-Fragment:  onDestroyView 
08-14 11:01:48.129 D 10628    10628    ScreenRotationActivity-Fragment:  onDetach 
08-14 11:01:48.199 D 10628    10628    ScreenRotationActivity-Fragment:  onCreate 
08-14 11:01:48.199 D 10628    10628    ScreenRotationActivity:           onCreate 
08-14 11:01:48.229 D 10628    10628    ScreenRotationActivity-Fragment:  onCreateView 
转屏完成

 6.2.3 解决方案三： Fragment生命周期 onPause之后 onDestroyView之前，会执行 onSaveInstanceState 方法。

    生命周期如下：

08-14 11:39:50.149 D 12536    12536    ScreenRotationActivity-Fragment:  onPause 
08-14 11:39:50.149 D 12536    12536    ScreenRotationActivity-Fragment:  onSaveInstanceState 
08-14 11:39:50.149 D 12536    12536    ScreenRotationActivity-Fragment:  onDestroyView 
08-14 11:39:50.159 D 12536    12536    ScreenRotationActivity-Fragment:  onDestroy 
08-14 11:39:50.159 D 12536    12536    ScreenRotationActivity-Fragment:  onDetach 
08-14 11:39:50.209 D 12536    12536    ScreenRotationActivity-Fragment:  onCreate 
08-14 11:39:50.209 D 12536    12536    ScreenRotationActivity:           onCreate 
08-14 11:39:50.229 D 12536    12536    ScreenRotationActivity-Fragment:  onCreateView 

    我们可以在onSaveInstanceState方法中，保存关键数据

@Override
public void onSaveInstanceState(Bundle outState) {
    // TODO Auto-generated method stub
    Log.d(TAG, "onSaveInstanceState");
    outState.putString("carloz", "Carlo Zhang");
    super.onSaveInstanceState(outState);
}
@Override
public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    Log.d(TAG, "onCreate");
    if(null != savedInstanceState) {
        Log.d(TAG, "onCreate: " + savedInstanceState.getString("carloz"));
    }
}

    结果如下：

08-14 11:44:51.949 D 13933    13933    ScreenRotationActivity:            onCreate 
08-14 11:44:51.959 D 13933    13933    ScreenRotationActivity:            onCreate: new FragmentA 
08-14 11:44:51.979 D 13933    13933    ScreenRotationActivity-Fragment:   onCreate 
08-14 11:44:51.979 D 13933    13933    ScreenRotationActivity-Fragment:   onCreateView 
开始转屏
08-14 11:44:55.249 D 13933    13933    ScreenRotationActivity-Fragment:   onPause 
08-14 11:44:55.259 D 13933    13933    ScreenRotationActivity-Fragment:   onSaveInstanceState 
08-14 11:44:55.259 D 13933    13933    ScreenRotationActivity-Fragment:   onDestroyView 
08-14 11:44:55.259 D 13933    13933    ScreenRotationActivity-Fragment:   onDestroy 
08-14 11:44:55.259 D 13933    13933    ScreenRotationActivity-Fragment:   onDetach 
08-14 11:44:55.329 D 13933    13933    ScreenRotationActivity-Fragment:   onCreate 
08-14 11:44:55.329 D 13933    13933    ScreenRotationActivity-Fragment:   onCreate: Carlo Zhang 
08-14 11:44:55.329 D 13933    13933    ScreenRotationActivity:            onCreate 
08-14 11:44:55.349 D 13933    13933    ScreenRotationActivity-Fragment:   onCreateView 
转屏完成

其他如 保存在文件或者数据库中的方法就不再列举了

7. Fragment 与 Activity 通信

  7.1 Activity 向 Fragment 传递数据

     在Activity中创建Bundle数据包，并调用Fragment的setArguments(Bundle bundle)方法，即可将Bundle数据包 传给Fragment

  7.2 Fragment 向 Activity 传递数据

    定义一个CallBack接口，让Activity实现改接口，在Fragment中即可调用该Callback的接口，代码见 5.1

-------------------------------------------

 工程代码：FragmentDemo.zip