WindowFromPoint的返回值是0怎么处理

Question

[StructLayout (LayoutKind.Sequential)]
        public class point
        {            public int  x;
            public int  y;
            public point(int  _x, int  _y)
            {                x = _x;
                y = _y;
            }
        }
 point _point = Control.MousePosition;
                    IntPtr hwyunyong = WindowFromPoint(_point);
hwyunyong 值总是为0 ，怎么处理？谢谢

Answer 1

本身没看出有什么错。    // 按着鼠标移动看效果
    public Form1()
    {
        InitializeComponent();
        this.MouseMove += delegate { this.Text = "Handle:" + WindowFromPoint(Control.MousePosition); };
    }    [DllImport("user32.dll", SetLastError=true)]
    static extern IntPtr WindowFromPoint(System.Drawing.Point Point);