用api(GetWindowRect)获取窗体矩形的问题

Question

代码如下:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;namespace GetHWND
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        //根据类名和窗体标题查找该窗体句柄
        [DllImport("user32.dll", EntryPoint = "FindWindowEx")]
        public static extern IntPtr FindWindowEx(
        int hWnd1,
        int hWnd2,
        string lpsz1,
        string lpsz2
        );        // 获得窗口矩形
        [DllImport("user32")]
        public static extern int GetWindowRect(int hwnd, ref RECT lpRect);
        // 获得客户区矩形
        [DllImport("user32.dll")]
        public static extern int GetClientRect(IntPtr hWnd, ref RECT lpRect);        // 矩形结构
        [StructLayout(LayoutKind.Sequential)]
        public struct RECT
        {
            int left;
            int top;
            int right;
            int bottom;
        }        private void Form1_Load(object sender, EventArgs e)
        {
        }        private void button1_Click(object sender, EventArgs e)
        {
            IntPtr i = FindWindowEx(0, 0, "#32770", "多多游戏-对对碰V2.24");
            RECT rc=new RECT();
            if (i.ToInt32() != 0)
            {
                GetWindowRect(i, ref rc);
                messagebox.show( rc.left)==================>此处,无法用rc.点出任何属性.而用断点查看,发现rc中的确有值
            }
            
        }
    }
}
分数不富裕,还请理解.