Android Fragment基礎及使用

同一個app內的界面切換 用Fragment比較合適，因為Activity比較重量級

Fragment 輕量級，切換靈活

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

1. 創建和使用 Fragment

2. Fragment 的生命周期 及相關的實際應用

3. 創建一個帶側邊欄的 Activity 以及使用

4. 創建一個 Tabbed Activity 並使用

5. 多個Fragment的切換和狀態保存

6. Fragment的橫豎屏切換

7. Fragment 與 Activity通信

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

工程代碼：FragmentDemo.zip

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

1. 創建和使用 Fragment

     * 創建一個 帶Fragment的Activity，將Fragment重構到一個新文件中PlaceholderFragment.java

     * 創建另一個Fragment，AnotherFragment.java

     * 使用按鈕實現兩個Fragment的切換

1.1 在layout fragment_main中添加一個按鈕btnOpenAnohterFragment， 用於打開另一個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) //支持返回鍵,否則點返回直接退出app
                                .replace(R.id.container, new AnotherFragment())
                                .commit();
                    }
                });
        return rootView;
    }
}

1.2 在AnotherFragment 添加按鈕btnBack，用於返回上一個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 及相關的實際應用

比Activity的生命周期多很多，

onCreate，onCreateView，onPause是最常用的

    創建兩個Fragment， A， B

        1. 打開FragmentA -> 暫停FragmentA -> 恢復FragmentA  -> 關閉FragmentA，生命周期變化如下

打開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 活動

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

恢復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. 打開FragmentA -> 由FragmentA打開FragmentB  -> 從FragmentB返回FragmentA，生命周期變化如下

打開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 

從A 打開 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內部的View組件完成
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處於穩定狀態
從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，兩個Fragment使用replace方法切換的時候，是A完全銷毀以后，才加載的B

 

3. 創建一個帶側邊欄的 Activity 以及使用

    新建 SliderActivity： 類型Navigation Drawer Activity， 可以看到SDK默認創建了幾個文件

SliderActivity.java
NavigationDrawerFragment.java

activity_slider.xml
fragment_navigation_drawer.xml
fragment_slider.xml

 

    * 默認效果： onCreateView中有一個ListView，來顯示數據

        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語句，即可出現如下效果

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;
    }
}

   

    * 自定義側邊欄

 

      創建一個Fragment：CarlozLibFragment.java，並為其創建一個布局carloz_lib_webview.xml，內部有一個WebView控件，順便在AndroidManifest.xml中添加Intent訪問權限；在CarlozLibFragment中重寫onCreateView方法，讓WebView訪問我的個人網站（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;
    }
}

      將NavigationDrawerFragment.java 中 onCreateView中ListView相關內容刪除，用自定義布局 diy_slider_content.xml （目錄res/layout）替換；diy_slider_content中定義了一個按鈕，用來打開剛剛創建的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) {
                // 隱藏側邊欄
                mDrawerLayout.closeDrawer(mFragmentContainerView);
            }
            if(mCallbacks != null) {
                mCallbacks.onGotoCarlozLibClicked();
            }
        }
    });
    
    return root;
}

      onGotoCarlozLibClicked()這個接口是自定義接口，在 靜態接口 NavigationDrawerCallbacks 中新增定義

public static interface NavigationDrawerCallbacks {
    /**
     * Called when an item in the navigation drawer is selected.
     */
    void onNavigationDrawerItemSelected(int position);
    
    // 通過回調傳給主界面
    void onGotoCarlozLibClicked();
}

    需要在主界面SliderActivity中實現該回調方法， 因為主界面實現了 NavigationDrawerFragment.NavigationDrawerCallbacks 接口

@Override
public void onGotoCarlozLibClicked() {
    // 需要實現 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();
}

運行結果如下：

 

4. 創建一個 Tabbed Activity 並使用

 默認樣式：

自定義：

    * 創建drawble目錄，並在里面放三張圖片img1, img2, img3；

    * 創建三個ImageFragment， 分別加載三種圖片

    * 在 TabsActivity 中調用三個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);
    }

結果如下

 

5. 多個Fragment的切換和狀態保存

    Fragment的操作有 add， replace， remove三個方法

    從2可以看出，使用replace方法來切換Fragment時會完全銷毀上一個Fragment，這樣再切換回上一個Fragment時，它的狀態就會丟失；

 

    5.1 現在 有一個問題，當一個Activity中 使用了 多個同級Fragment，那么多個Fragment切換時如何保存Fragment的狀態？

 

    智慧的網友們給出了解決方案：把用到的Fragment全部使用add方法添加， 使用hide、show方法來控制，需要使用哪個，就顯示哪個。缺點是：幾個Fragment會一直占用內存，直到Fragment銷毀

    定義一個Activity：FragmentSwitchActivity，用於存放Fragment

    定義兩個Fragment：PlaceholderFragment 和 FragmentSwitch1，用於演示 切換操作

    定義一個Callback：FragmentSwitchCallBack，用於管理Fragment 和 切換邏輯

    使用這個Callback，控制再多的Fragment都行，這里為了簡單，只控制兩個

public interface FragmentSwitchCallBack {
    //使用一個List管理當前添加的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中實現該CallBack，用來管理 Fragment List， 將需要的Fragment顯示，不需要的隱藏：

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);
        }
    }
}

        兩個Fragment切換時的生命周期如下

打開FragmentSwitchActivity，順便添加第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 
打開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 
以后再切換，生命周期不再變化

 

    5.2 二級Fragment的狀態保存

       此問題以后再分析~

 

6. 單個Fragment的橫豎屏切換及狀態保存

6.1 橫豎屏切換時的Fragment生命周期變化如下， 會先銷毀，再重新創建

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 默認情況下橫豎屏切換后整個FragmentActivity會被銷毀並重建，所有Fragment中的成員變量也會丟失，但所有的Fragment狀態數據如上所述會被保留並還原，這個時候所有的視圖都會重新創建。

未采取任何解決方案時的轉屏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 
開始轉屏
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 
轉屏完成

6.2.1 解決方法一：在相應的Activity配置中加上android:configChanges="orientation|screenSize"設置，這樣切換時就不會銷毀FragmentActivity,所有的Fragment的狀態及視圖也就會保持。

<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");
}

使用解決方案一以后的生命周期變化如下，可以解決問題：

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 
開始轉屏
08-14 10:21:26.249 D 7697  7697  ScreenRotationActivity:           onConfigurationChanged 
轉屏完成

6.2.2 解決方法二：在使用FragmentTransaction.add()方法添加fragment時設置第三個tag參數,隨后在還原時可通過FragmentManager.findFragmentByTag()方法找回還原的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();
}

    經我實驗，Fragment雖然找回來了，但是還是回執行onCreateView方法，UI組件狀態已丟失，哪位大神有好的方法，請@我， 簡略版生命周期如下

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 
開始轉屏
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 
轉屏完成

 6.2.3 解決方案三： Fragment生命周期 onPause之后 onDestroyView之前，會執行 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 

    我們可以在onSaveInstanceState方法中，保存關鍵數據

@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")); }
}

    結果如下：

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 
開始轉屏
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 
轉屏完成

 

其他如 保存在文件或者數據庫中的方法就不再列舉了

 

7. Fragment 與 Activity 通信

  7.1 Activity 向 Fragment 傳遞數據

     在Activity中創建Bundle數據包，並調用Fragment的setArguments(Bundle bundle)方法，即可將Bundle數據包 傳給Fragment

  7.2 Fragment 向 Activity 傳遞數據

    定義一個CallBack接口，讓Activity實現改接口，在Fragment中即可調用該Callback的接口，代碼見 5.1

 

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

 工程代碼：FragmentDemo.zip