小编and*_*uae的帖子

我正在构建一个由谷歌文档设计的导航抽屉,但我有一个问题,片段没有被替换.http://developer.android.com/training/implementing-navigation/nav-drawer.html

应用程序首次加载时,将加载默认片段.单击抽屉列表上的另一个项目会留下空视图但是在旋转设备时,会加载所选的片段.

public void selectNavActivty(int position){
    // TODO Changing between the different screens selection
    fragment = null;
    switch (position) {
        case 0:
            fragment = OverLay.newInstance();
            break;
        case 1: 
            fragment = Dummy.newInstance();
            break;
        }

    if(fragment != null) {
        // attach added to handle viewpager fragments
        FragmentTransaction trans = getSupportFragmentManager().beginTransaction();
        trans.replace(R.id.content_frame, fragment).attach(fragment)
            .addToBackStack(null);

        trans.commit();
        getFragmentManager().executePendingTransactions();
    } else {
        Log.d("Drawer Activity","Error in creating Fragment");
    }
}