基本思路:

方法1.遮罩可直接叠加一层带alpha的纯白、或纯黑View,可直接在ImageView外套一层FrameLayout,其foreground(一般同学可能仅仅知道background,事实上framelayout还有foreground)给定一个selector(按下时给0x33000000,即泛黑),到位。

方法2.重写imageView,按下状态改变时invalidate(触发onDraw),onDraw中依据按下状态绘制0x33000000。注意imageView.setClickable(true),或imageView.setOnClickListener时才可触发dispatchSetPressed。

@Override	public void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);		// 取id		// imgTest = (ImageView) findViewById(R.id.imgTest);		loMain = (RelativeLayout) findViewById(R.id.loMain);		findViewById(R.id.btn1).setOnClickListener(this);		findViewById(R.id.btn2).setOnClickListener(this);		MyImg myImg = new MyImg(this);		myImg.setImageResource(R.drawable.meinv);		myImg.setClickable(true);		loMain.addView(myImg);	}	private class MyImg extends ImageView {		public MyImg(Context context) {			super(context);		}		@Override		protected void onDraw(Canvas canvas) {			// TODO Auto-generated method stub			super.onDraw(canvas);			if (isPressed())				canvas.drawColor(0x33000000);		}		@Override		protected void dispatchSetPressed(boolean pressed) {			// TODO Auto-generated method stub			super.dispatchSetPressed(pressed);			invalidate();		}	}