安卓使用window manager往屏幕上添加一个view

如何往屏幕中任意位置添加一个view。
直接上代码

一、获取window manager

WindowManager windowManager = getWindowManager();

二、实例化你要添加的控件

ImageView imageView = new ImageView(context);

三、设置layoutparams，注意这里要用到WindowManager.LayoutParams

WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
layoutParams.format = PixelFormat.RGBA_8888;
layoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
layoutParams.width = 30;
layoutParams.height = 30;
layoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;

layoutParams.gravity = Gravity.BOTTOM | Gravity.LEFT;
layoutParams.x = 30;
layoutParams.y = 40;

在这里可以具体设置视图所添加到的位置

四、将view 和 布局参数add进window

windowManager.addview(imageView ,layoutParams);

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