LocationOnScreen-控件在手机屏幕中的位置坐标

我们可以通过如下的方法获得某个控件在屏幕中的绝对坐标

代码如下：

 private int[] mHistoryDisplayButtonLocation;
 private int mHistoryDisplayButtonLocationX;
 private int mHistoryDisplayButtonLocationY;

mHistoryDisplayButtonLocation = new int[2];
mHistoryDisplayButton.getLocationOnScreen(mHistoryDisplayButtonLocation);
mHistoryDisplayButtonLocationX = mHistoryDisplayButtonLocation[0];
mHistoryDisplayButtonLocationY = mHistoryDisplayButtonLocation[1];

如果你把上面这段代码放到onCreate中执行，那么你会发现，打印的结果是0

后来网上找答案，说是定位坐标需要时间。但是，在另一篇文章中看到了真正的解决方法

原来，我们需要把上面得到坐标的操作放到

onWindowFocusChanged    方法中去执行

 @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        mHistoryDisplayButton.getLocationOnScreen(mHistoryDisplayButtonLocation);
        mHistoryDisplayButtonLocationX = mHistoryDisplayButtonLocation[0];
        mHistoryDisplayButtonLocationY = mHistoryDisplayButtonLocation[1];

        super.onWindowFocusChanged(hasFocus);
}