Question

我需要一些解释/建议，也许还有一些示例如何使用Fragments替换我的ActivityGroup类。我在一年前使用已弃用的TabActivity组合ActivityGroup编写了该应用程序，因此在进入不同的活动时我仍然可以保留标签。所以现在我想重写我的应用程序并使用新的API，我真的很好奇如何使用带有片段的活动重写方法和整个想法，并在与应用程序的整个交互过程中保留标签栏。我不需要使用新标签和TabActivity替换ActionBar。这是我的TabGroupActivity的一个示例，我用它来保持应用程序底部的标签栏：

    public class TabGroupActivity extends ActivityGroup {

    private ArrayList<String> mIdList;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);       
        if (mIdList == null) mIdList = new ArrayList<String>();
    }

    /*
     * This is called when a child activity of this one calls its finish method. 
     * This implementation calls {@link LocalActivityManager#destroyActivity} on the child activity
     * and starts the previous activity.
     * If the last child activity just called finish(),this activity (the parent),
     * calls finish to finish the entire group.
     */
  @Override
  public void finishFromChild(Activity child) {
      LocalActivityManager manager = getLocalActivityManager();
      int index = mIdList.size()-1;

      if(index < 1) {
              finish();
              return;
      } 

      try {
            manager.destroyActivity(mIdList.get(index), true);
            mIdList.remove(index);
            index--;
            String lastId = mIdList.get(index);
            if(manager.getActivity(lastId).getIntent() == null){
                finish();
            } else if(manager.getActivity(lastId).getIntent() != null){
                Intent lastIntent = manager.getActivity(lastId).getIntent();
                Window newWindow = manager.startActivity(lastId, lastIntent);
                setContentView(newWindow.getDecorView());
            }
      }catch (NullPointerException e){
          finish();
      }

  }

  /*
   * Starts an Activity as a child Activity to this.
   * @param Id Unique identifier of the activity to be started.
   * @param intent The Intent describing the activity to be started.
   * @throws android.content.ActivityNotFoundException.
   */
  public void startChildActivity(String Id, Intent intent) {     
      Window window = getLocalActivityManager().startActivity(Id,intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
      if (window != null) {
          mIdList.add(Id);
          setContentView(window.getDecorView()); 
      }    
  }

  /*
   * The primary purpose is to prevent systems before android.os.Build.VERSION_CODES.ECLAIR
   * from calling their default KeyEvent.KEYCODE_BACK during onKeyDown.
   */
  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {
      if (keyCode == KeyEvent.KEYCODE_BACK) {
          //preventing default implementation previous to android.os.Build.VERSION_CODES.ECLAIR
          return true;
      }
      return super.onKeyDown(keyCode, event);
  }

  /*
   * Overrides the default implementation for KeyEvent.KEYCODE_BACK 
   * so that all systems call onBackPressed().
   */
  @Override
  public boolean onKeyUp(int keyCode, KeyEvent event) {
      if (keyCode == KeyEvent.KEYCODE_BACK) {
          onBackPressed();
          return true;
      }
      return super.onKeyUp(keyCode, event);
  }

  /*
   * If a Child Activity handles KeyEvent.KEYCODE_BACK.
   * Simply override and add this method.
   */
  @Override
  public void  onBackPressed () {
      int length = mIdList.size();
      if ( length >=1) {
          Activity current = getLocalActivityManager().getActivity(mIdList.get(length-1));
          try{
              current.finish();
          }catch(Exception e){
              finish();
          }

      }
  }
}

所以基本上我需要一些帮助来理解如何实现与Instagram应用程序中相同的交互。

非常感谢各种帮助！

Answer 1

在我的情况下，我使用了android支持库中的FragmentManager V4和带有Fragments的tabhost，并使用了一些东西。如果有人需要一个示例，您可以在Android开发者博客中找到它，或者只是在Google上搜索Android碎片示例，您会发现一些有用的东西。：）

Android用Fragments / FragmentsManager替换ActivityGroup

1 个答案: