无法从片段中投射

Question

我在我的布局中定义了两个片段MainActivity并设置了setContentView.我想从这些片段中调用一些方法,但我不知道如何访问它们.Eclipse说:"无法将表单片段转换为ListFileFrgament".

public class MainActivity extends FragmentActivity {

    @Override
     protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    FileListFragment listFragment = (FileListFragment) getFragmentManager().findFragmentById(R.id.list_fragment);  
     // cannot casr here
    PlayerFragment playerFragment = (PlayerFragment) getFragmentManager().findFragmentById(R.id.player_fragment); 
     // cannot cast here
    }


}

Answer 1

用getSupportFragmentManager()而不是getFragmentManager()

Answer 2

确保你的导入匹配 - 可能是FileListFragment/PlayerListFragment扩展android.support.v4.app.Fragment而getFragmentManager().findFragmentById返回android.app.Fragment.

使用getSupportFragmentManager()返回android.support.v4.app.Fragment实例.