Android 获取 屏幕状态栏高度和标题栏高度 避免出现0的情况

@Override  
    public void onWindowFocusChanged(boolean hasFocus) {  
        super.onWindowFocusChanged(hasFocus);  
  
        Rect frame = new Rect();  
        getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);  
        int statusBarHeight = frame.top;  
        // 获取标题栏高度  
        Window window = getWindow();  
        int contentViewTop = getWindow()  
                .findViewById(Window.ID_ANDROID_CONTENT).getTop();  
        // statusBarHeight是上面所求的状态栏的高度  
        titleBarHeight = contentViewTop - statusBarHeight;  
  
        Log.i("test", "statusBarHeight=" + statusBarHeight + " contentViewTop="  
                + contentViewTop + " titleBarHeight=" + titleBarHeight);  
    }