正在运行的 Alertdialog 不会关闭或取消

Question

根据answer，我想显示 dilaog，直到加载接下来的 10 个帖子，所以我创建了静态 alertDialog 方法以在我的应用程序的不同位置使用它，但问题是对话框不会取消或关闭

setProgressDialog 在 Utils 类中

 public static AlertDialog setProgressDialog(Context context) {

        int llPadding = 30;
        LinearLayout ll = new LinearLayout(context);
        ll.setOrientation(LinearLayout.HORIZONTAL);
        ll.setPadding(llPadding, llPadding, llPadding, llPadding);
        ll.setGravity(Gravity.CENTER);
        LinearLayout.LayoutParams llParam = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);
        llParam.gravity = Gravity.CENTER;
        ll.setLayoutParams(llParam);

        ProgressBar progressBar = new ProgressBar(context);
        progressBar.setIndeterminate(true);
        progressBar.setPadding(0, 0, llPadding, 0);
        progressBar.setLayoutParams(llParam);

        llParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
        llParam.gravity = Gravity.CENTER;
        TextView tvText = new TextView(context);
        tvText.setText("Loading ...");
        tvText.setTextColor(context.getResources().getColor(R.color.black));
        tvText.setTextSize(20);
        tvText.setLayoutParams(llParam);

        ll.addView(progressBar);
        ll.addView(tvText);

        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setCancelable(false);
        builder.setView(ll);

        AlertDialog dialog = builder.create();
        dialog.show();
        Window window = dialog.getWindow();
        if (window != null) {
            WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
            layoutParams.copyFrom(dialog.getWindow().getAttributes());
            layoutParams.width = LinearLayout.LayoutParams.WRAP_CONTENT;
            layoutParams.height = LinearLayout.LayoutParams.WRAP_CONTENT;
            dialog.getWindow().setAttributes(layoutParams);
        }
        return dialog;
    }

然后我在 HomeFragment 点击加载更多按钮时使用它

binding.loadMoreBtn.setOnClickListener(view -> {

            Utils.setProgressDialog(requireContext());

            if (Utils.hasNetworkAccess(requireContext())) {
                postViewModel.getPosts();
//                Log.w(TAG, "loadMoreBtn: "+dialog.isShowing() );
            } else {
                postViewModel.getAllItemsFromDataBase.getValue();
            }
            Utils.setProgressDialog(requireContext()).cancel();
            Utils.setProgressDialog(requireContext()).dismiss();

        });

PS：我也尝试创建对话框AlertDialog dialog = Utils.setProgressDialog(requireContext());，而不是直接调用该方法然后dialod.show()，并在getPosts 之后取消或关闭它但它不会出现

Answer 1

我通过在视图模型中添加一个标志布尔值来检测加载状态来修复它

public final MutableLiveData<Boolean> isLoading = new MutableLiveData<>();

并像这样在getPosts() 中使用它

public void getPosts() {
        Log.e(TAG, finalURL.getValue());

        isLoading.setValue(true);
        repository.remoteDataSource.getPostList(finalURL.getValue())
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Observer<Response<PostList>>() {
                    @Override
                    public void onSubscribe(@NonNull Disposable d) {

                    }

                    @Override
                    public void onNext(@NonNull Response<PostList> postListResponse) {

                        if (postListResponse.isSuccessful()) {
                            if (postListResponse.body() != null
                                    && postListResponse.body().getNextPageToken() != null) {
                                Log.e(TAG, postListResponse.body().getNextPageToken());
                                token.setValue(postListResponse.body().getNextPageToken());
                                isLoading.setValue(false);
                            }
                            postListMutableLiveData.setValue(postListResponse.body());

最后在按钮点击的片段中

binding.loadMoreBtn.setOnClickListener(view -> {
            AlertDialog dialog = Utils.setProgressDialog(requireContext());

            postViewModel.isLoading.observe(getViewLifecycleOwner(), isLoading -> {
                if (isLoading) {
                    dialog.show();
                } else {
                    dialog.dismiss();
                }
            });

            if (Utils.hasNetworkAccess(requireContext())) {
                postViewModel.getPosts();
                Log.w(TAG, "loadMoreBtn: " + dialog.isShowing());
            } else {
                postViewModel.isLoading.postValue(true);
                postViewModel.getAllItemsFromDataBase.getValue();
                postViewModel.isLoading.postValue(false);
            }

        });

Answer 2

binding.loadMoreBtn.setOnClickListener(view -> {

        Utils.setProgressDialog(requireContext());

        if (Utils.hasNetworkAccess(requireContext())) {
            postViewModel.getPosts(); //                Log.w(TAG, "loadMoreBtn: "+dialog.isShowing() );
        } else {
            postViewModel.getAllItemsFromDataBase.getValue();
        }
        Utils.setProgressDialog(requireContext()).cancel();
        Utils.setProgressDialog(requireContext()).dismiss();

    });

这里你多次调用了静态方法Utils.setProgressDialog()；并且每次调用它时，它都会返回一个全新的对话框，因此您可以关闭一个未显示在屏幕上的对话框。

相反，您需要将第一次调用该方法返回的对话框存储到一个变量中：

AlertDialog dialog = Utils.setProgressDialog(requireContext());

然后在该对话框版本上调用 dismiss：dialog.dismiss() 或 dialog.cancel()，只要您需要关闭它。