TV开发中，当进入某一个界面没有焦点，或者遥控器怎么点击都找不到焦点 寻找当前焦点所在view，在Activity中：
new Thread(run).start();
Runnable run = new Runnable() {
@Override
public void run() {
while (true) {
try {
Thread.sleep(5000);
View rootview = NotificationCenterActivity.this.getWindow().getDecorView();
View focusView = rootview.findFocus();
LogUtil.i(TAG, "focusView: " + focusView.toString());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
};
