小吃店不能立即显示

Question

i'm trying to save a image when an ImageView is clicked. Because the saving takes some time i want to have some sort of indicator, that the app is working. I tried to use Snackbar for that. My code looks something like this:

File image = new File(directory, "image.png");

        if(!image.exists()){

            Snackbar bar = Snackbar.make(getActivity().findViewById(R.id.some_layout), "snackText", Snackbar.LENGTH_INDEFINITE);
            bar.show();

            FileOutputStream outStream = null;
            try {
               outStream = new FileOutputStream(image);
               bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
               outStream.flush();
               outStream.close();
            } catch (FileNotFoundException e) {
               e.printStackTrace();
            } catch (IOException e) {
               e.printStackTrace();
            }

            bar.dismiss();
        }

All that is inside the public void onClick(View view) of that ImageView. The problem is, that the Snackbar only shows after the image is saved. I tried to force update the UI with invalidate() and tried it without starting a new Thread with the same result. Any ideas are greatly appreciated!

Answer 1

Don't use snackbar here edit your code like this: if(!image.exists()){

        final ProgressDialog progressDialog =ProgressDialog.show(this, "","Please Wait...", true);

        Thread t = new Thread(new Runnable() {
            @Override
            public void run() {
                FileOutputStream outStream = null;
                try {
                    outStream = new FileOutputStream(image);
                    bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
                    outStream.flush();
                    outStream.close();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        progressDialog.dismiss();
                    }
                });

            }

        });
        t.start();

        try {
            t.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }