android - 无法用新片段替换片段

Question

我正在尝试在另一个 Fragment 中替换一个 Fragment，但我感到很奇怪NullPointerException，请你看看并告诉我你的想法吗？

这是我的代码：

public class HomeScreenFragment extends Fragment implements FolderViewInterface {
//stuff before this

@Override
    public void onFolderOpened(int folder_index) {
        System.out.println("THe callback brought me here, passed index:"+folder_index);

        Fragment newFragment = new FolderViewFragment(); 
        // consider using Java coding conventions (upper char class names!!!)
        FragmentTransaction transaction = getFragmentManager().beginTransaction();

        // Replace whatever is in the fragment_container view with this fragment,
        // and add the transaction to the back stack
        transaction.replace(R.id.fragment_container, newFragment);
        transaction.addToBackStack(null);

        // Commit the transaction
        transaction.commit(); 

    }
}

堆栈跟踪：

08-01 16:48:11.587: E/AndroidRuntime(14399): FATAL EXCEPTION: main
08-01 16:48:11.587: E/AndroidRuntime(14399): java.lang.NullPointerException
08-01 16:48:11.587: E/AndroidRuntime(14399):    at ro.gebs.captoom.fragments.HomeScreenFragment.onFolderOpened(HomeScreenFragment.java:320)
08-01 16:48:11.587: E/AndroidRuntime(14399):    at ro.gebs.captoom.utils.FolderListView.onInterceptTouchEvent(FolderListView.java:48)
08-01 16:48:11.587: E/AndroidRuntime(14399):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2110)
08-01 16:48:11.587: E/AndroidRuntime(14399):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2470)
08-01 16:48:11.587: E/AndroidRuntime(14399):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2212)
08-01 16:48:11.587: E/AndroidRuntime(14399):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2470)

我通过回调到达这里，我在处理触摸事件的 ListView 上下文中。欢迎任何建议。

Answer 1

您的 FragmentManager 看起来为空。尝试使用 getChildFragmentManager()。