请问：Android imageview一直驻留屏幕按退出也不被覆盖怎么实现的了？

Question

mWindowManager = (WindowManager)mContext.getApplicationContext().getSystemService("window"); mParams = new WindowManager.LayoutParams();
mParams.type = LayoutParams.TYPE_PHONE;
mParams.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL | LayoutParams.FLAG_NOT_FOCUSABLE | LayoutParams.FLAG_NOT_TOUCHABLE; // 这里是设置只是悬浮而点击不到
mParams.gravity = Gravity.LEFT|Gravity.TOP;
mParams.x = 10;
mParams.y = 10;
mParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
mParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
mParams.alpha = 0.5f; mWindowManager.addView(imageView, mParams);<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>