Android Studio（Chipmunk）屏幕截图图像变暗

Question

I am programming a simple drawing application with drawLines:

public void onDraw(Canvas canvas) {
        setBackgroundColor(cfgBackground); //background
        //canvas.drawColor(ConfigActivity.getCfgBackground(ConfigActivity.cfgBackground)); //to keep background when export to PNG/JPG
        //title
        paint.setColor(0xbb020a0d);
        paint.setTextSize(40);
        canvas.drawText(Title, 0, 40, paint);

        paint.setColor(color);
        paint.setStrokeWidth(thickness);
        canvas.drawLines(lines, paint);
}

This is no problem. When export the screen to image file, the image shows normal in the preview screen (with all other photos in the phone), but when open this image, it shows darken, as following:

I have tried Method A/B/C like following, but the result not much different:

        File sdCard = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
        File file = new File(sdCard, imageName);
        FileOutputStream fos = null;
        try {
            // Make sure the Pictures directory exists.
            sdCard.mkdirs();

            fos = new FileOutputStream(file);  
        } catch (FileNotFoundException e) {
            Toast.makeText(getContext(), file + " open failed: " + e, Toast.LENGTH_SHORT).show();
            e.printStackTrace();
            return;
        }

        /*  //method A: will get dark image
        setDrawingCacheEnabled(true);
        Bitmap b = getDrawingCache();
        //b.setHasAlpha(true); //to set transparency
        //Canvas canvas = new Canvas(b);
        //canvas.drawColor(cfgBackground)); //trying to solve darken image
        b.compress(Bitmap.CompressFormat.PNG, 100, fos);
        setDrawingCacheEnabled(false); //for next screen update
        */
        Bitmap b = screenShot(this); //Method B
        b.compress(Bitmap.CompressFormat.PNG, 100, fos);
        try {
            fos.flush();
            fos.close();
        } catch (IOException e) {
            Toast.makeText(getContext(), file + " save failed: " + e, Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }
        Toast.makeText(getContext(), file + " saved in Albums", Toast.LENGTH_SHORT).show();
        //add to gallary
        getContext().sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://" + file.toString())));

Two functions:

    //Method C
    public static Bitmap getBitmapFromView(View view) {
        //Define a bitmap with the same size as the view
        Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
        //Bind a canvas to it
        Canvas canvas = new Canvas(returnedBitmap);
        //Get the view's background
        Drawable bgDrawable =view.getBackground();
        if (bgDrawable!=null)
            //has background drawable, then draw it on the canvas
            bgDrawable.draw(canvas);
        else
            //does not have background drawable, then draw white background on the canvas
            canvas.drawColor(cfgBackground);
        // draw the view on the canvas
        view.draw(canvas);
        //return the bitmap
        return returnedBitmap;
    }
    //Method B
    public Bitmap screenShot(View view) {  
        Bitmap bitmap = Bitmap.createBitmap(view.getWidth(),
                view.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        view.draw(canvas);
        return bitmap;
    }

Anyone encountered this problem?

Answer 1

I finally found the solution (although not sure why): the background color should be 0xFFrrggbb, eg. 0xffeeee00, though the background looks ugly but just needs more finetune... If you know why, kindly share here, appreciated!