int Msg, // 消息ID
int wParam, // 参数1
ref My_lParam lParam //参数2
);
//异步消息发送API
[DllImport("User32.dll", EntryPoint = "PostMessage")]
public static extern int PostMessage(
IntPtr hWnd, // 信息发往的窗口的句柄
int Msg, // 消息ID
int wParam, // 参数1
ref COPYDATASTRUCT lParam // 参数2
);
}
}
//主窗体，发送消息
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace TestHwnd
{
public partial class Main : Form
{
public IntPtr hwndTest;
public int IwndTest;
public IntPtr hwndfrmTest;
public Main()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Test test = new Test();
test.Show(this);
}
private void timer1_Tick(object sender, EventArgs e)
{
string strTest = "25425";
Win32API.COPYDATASTRUCT cds;
cds.dwData = (IntPtr)100;
cds.lpData = strTest;
byte[] sarr = System.Text.Encoding.UTF8.GetBytes(strTest);
int len = sarr.Length;
cds.cbData = len + 1;
Win32API.My_lParam lp=new Win32API.My_lParam();
lp.i=3;
lp.s="test";
if(hwndTest!=(IntPtr)0)
{
if (DateTime.Now.Second % 2 == 0)
{
Win32API.SendMessage(hwndTest, 0x60, 1, 3);//传递2个整型参数成功
}
if(DateTime.Now.Second % 3 == 0)
{
Win32API.SendMessage(hwndTest, 0x61, 5, ref lp);//传递整型参数和结构类型成功，这个方法加以改变后可以传递对象
}
if(DateTime.Now.Second % 5 == 0)
{
Win32API.SendMessage(hwndTest, 0x62, 5, ref cds);//传递整型参数和不定长的字符串成功
}
if(DateTime.Now.Second % 7 == 0)
{
Win32API.PostMessage(hwndTest, 0x63, 5, 6);//传递2个整型参数成功
}
if(DateTime.Now.Second % 9 == 0)
{
Win32API.PostMessage(hwndTest, 0x64, 3, ref lp);//传递整型参数成功，但是传递参数lp失败，3可以传递成功。
}
if(DateTime.Now.Second % 11 == 0)
{
Win32API.PostMessage(hwndTest, 0x65, 3, ref cds);//传递整型参数成功，传递参数cds失败，3可以传递成功。
}
}
}
}
}
//子窗体接收消息以及参数