小编gau*_*ari的帖子

我有一个弹出窗口,可以在我的应用程序中下载音频指令.我想要做的是我想将"OK"的默认文本颜色更改为蓝色.我试了一下,但它不起作用.这是我的代码:

 private void showDownloadPgmPopup() {

    android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(getActivity());
    builder.setTitle("Download instructional audio?");
    builder.setMessage(ParamConstants.AUDIODOWNLOADPERMISSION);
    builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            WwDatabaseHelper.storeSelectedWeekAndDay(getActivity(), mSelectedWeekDataModel);
            goToMoveScreen();
        }
    });
    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            AndroidDownloadFileByProgressBarActivity.StartAudioAssetDownload(getActivity());

        }

    }).create();
    // change the text color of download instruction ok button


    final android.app.AlertDialog dialog = builder.show();
    dialog.setOnShowListener( new DialogInterface.OnShowListener() {
                                  @Override
                                  public void onShow(DialogInterface arg0) {
                                      dialog.getButton(AlertDialog.BUTTON_POSITIVE).setTextColor(Color.parseColor("#ff5722"));
                                  }
                              });
    dialog.setCanceledOnTouchOutside(false);
    dialog.show();
}

但这种变化并没有反映任何人都可以告诉我我做错了什么？

我有一个带有 n 个项目的 recyclerView。每个项目都可以在单击时展开。我希望我的项目扩展以及移动到顶部 onCLick。假设如果我点击第三个项目，那么它应该移动到第一个项目的位置，然后它会扩展并且滚动应该停止。我已经设法用动画扩展 RecyclerView，但它没有在顶部位置移动。我也试过 scrollToPosition，但没有用。下面是我的活动类：

public class MainActivity extends AppCompatActivity {

   private RecyclerView recyclerView;

   ArrayList<Integer> catImg=new ArrayList<>();
   private CategoryAdapter mAdapter;
   RecyclerView.LayoutManager mLayoutManager;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
       recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
       catImg.add(R.drawable.eyebrowposition_wide);
       catImg.add(R.drawable.eyebrowthickness_question);
       catImg.add(R.drawable.eyebrowthickness_thick);
       catImg.add(R.drawable.eyebrowthickness_thin);

       mAdapter = new CategoryAdapter(this,catImg);

       recyclerView.setHasFixedSize(true);

       // vertical RecyclerView
       // keep movie_list_row.xml width to `match_parent`
       mLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayoutManager.VERTICAL, false);

       // horizontal RecyclerView
       // keep movie_list_row.xml width to `wrap_content`
       // RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayoutManager.HORIZONTAL, false);

       recyclerView.setLayoutManager(mLayoutManager);

       // adding …