android学习8——获取view在屏幕上的绝对坐标

获取view在屏幕上的绝对坐标在调试时候非常有用.
看如下代码

public class AbsolutePosActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new DrawLineView(this));
    }
}
public class DrawLineView extends View {
    @Override
    protected void onDraw(Canvas canvas) {
        Paint paint = new Paint();
        paint.setColor(Color.WHITE);
        canvas.drawLine(0, 0, 1536, 2048, paint);
        super.onDraw(canvas);
        int[] location = new int[2];
        getLocationOnScreen(location);
        Log.i("Logzy", "x=" + location[0] + ",y=" + location[1]);
        Log.i("Logzy", "width=" + getWidth() + ",height=" + getHeight());
    }
    public DrawLineView(Context context) {
        super(context);
    }
}

界面显示如下所示:

日志输入为:

01-06 07:55:00.552  24762-24762/edu.cgxy.absolutepos I/Logzy﹕ x=0,y=146
01-06 07:55:00.552  24762-24762/edu.cgxy.absolutepos I/Logzy﹕ width=720,height=1134

getLocationOnScreen得到了view左上角的坐标,单位是像素.
用以下代码去掉标题栏.

public class AbsolutePosActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(new DrawLineView(this));
    }
}

界面显示如下所示:

日志输入为:

01-06 07:59:42.608  25290-25290/edu.cgxy.absolutepos I/Logzy﹕ x=0,y=0
01-06 07:59:42.608  25290-25290/edu.cgxy.absolutepos I/Logzy﹕ width=720,height=1280

可以看到没有标题栏.view的左上解绝对坐标就是(0,0)
源代码地址:https://github.com/zhouyang209117/AndroidTutorial/tree/master/Game/ch4/AbsolutePos