仿微信聊天气泡 图片尖角 按下变暗

实现微信气泡图片尖角

//-------------gen corner bitmap flow------------------------
//load the bg: .9.png which is with cornor.
Bitmap bg = BitmapFactory.decodeResource(getResources(), R.drawable.chat_bg);
//combine bg and  the in bitmap ,size can be resized by custom.
public Bitmap getRoundCornerImage(Bitmap bg, Bitmap in) {
    Bitmap roundConcerImage = Bitmap.createBitmap(200, 200, Config.ARGB_8888);
    Canvas canvas = new Canvas(roundConcerImage);
    Paint paint = new Paint();
    Rect rect = new Rect(0, 0, 200, 200);
    Rect rectF = new Rect(0, 0, in.getWidth(), in.getHeight());
    paint.setAntiAlias(true);
    NinePatch patch = new NinePatch(bg, bg.getNinePatchChunk(), null);
    patch.draw(canvas, rect);
    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
    canvas.drawBitmap(in, rectF, rect, paint);
    return roundConcerImage;
}
//load the image to be shown as bitmap in.
Bitmap bp = getRoundCornerImage(bg,in);
//set bitmap to the imageview.
iv.setImageBitmap(bp);
//----------------finish---------------------

图片按下变暗效果：

/**
 * this is just a sample.
 * u can overide the imageview's onTouchEvent() method.
 **/
iv.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View arg0, MotionEvent arg1) {
                // TODO Auto-generated method stub
                if (arg1.getActionMasked() == MotionEvent.ACTION_DOWN) {
                    Drawable drawable = iv.getDrawable();
                    drawable.setColorFilter(Color.GRAY, PorterDuff.Mode.MULTIPLY);
                }
                if (arg1.getActionMasked() == MotionEvent.ACTION_UP) {
                    Drawable drawable = iv.getDrawable();
                    drawable.clearColorFilter();
                }
                return false;
            }
        });

simple and practical.