C# 进程间通信

使用SendMessage向另一进程发送WM_COPYDATA消息

Send端：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Runtime.InteropServices;

namespace SentTest
{
///

/// MainWindow.xaml 的交互逻辑
///

public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.Title = "发送窗口";
}

const int WM_COPYDATA = 0x004A;

public struct COPYDATASTRUCT
{
public IntPtr dwData;
public int cData;
[MarshalAs(UnmanagedType.LPStr)]
public string lpData;
}

[DllImport("User32.dll")]
public static extern int SendMessage(int hwnd, int msg, int wParam, ref COPYDATASTRUCT IParam);
[DllImport("User32.dll")]
public static extern int FindWindow(string lpClassName, string lpWindowName);

private void button1_Click(object sender, RoutedEventArgs e)
{
String strSent = "需要发送的信息";

int WINDOW_HANDLE = FindWindow(null, "接收窗口");
if (WINDOW_HANDLE != 0)
{
byte[] arr = System.Text.Encoding.Default.GetBytes(strSent);
int len = arr.Length;
COPYDATASTRUCT cdata;
cdata.dwData = (IntPtr)100;
cdata.lpData = strSent;
cdata.cData = len + 1;
SendMessage(WINDOW_HANDLE, WM_COPYDATA, 0, ref cdata);
}
}
}
}

Get端：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Runtime.InteropServices;
using System.Windows.Interop;

namespace GetTest
{
///

/// MainWindow.xaml 的交互逻辑
///

public partial class MainWindow : Window
{
IntPtr hwnd;
public MainWindow()
{
InitializeComponent();
this.Title = "接受窗口";

this.Loaded += new RoutedEventHandler(MainWindow_Loaded);
this.Closed += new EventHandler(MainWindow_Closed);
}

void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
//窗口加载完毕才可用，否则会报错。
hwnd = new WindowInteropHelper(this).Handle;
HwndSource source = HwndSource.FromHwnd(hwnd);
if (source != null) source.AddHook(WndProc);
}

void MainWindow_Closed(object sender, EventArgs e)
{
try
{
HwndSource.FromHwnd(hwnd).RemoveHook(WndProc);
}
catch (Exception)
{

throw;
}

}

const int WM_COPYDATA = 0x004A;//WM_COPYDATA消息的主要目的是允许在进程间传递只读数据。
//Windows在通过WM_COPYDATA消息传递期间，不提供继承同步方式。
//其中,WM_COPYDATA对应的十六进制数为0x004A
public struct COPYDATASTRUCT
{
public IntPtr dwData;
public int cData;
[MarshalAs(UnmanagedType.LPStr)]
public string lpData;
}

//wpf用此方法
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == WM_COPYDATA)
{
COPYDATASTRUCT cdata = new COPYDATASTRUCT();
Type mytype = cdata.GetType();
cdata = (COPYDATASTRUCT)Marshal.PtrToStructure(lParam, mytype);
this.textBox1.Text = cdata.lpData;
}
return IntPtr.Zero;
}

//WinFrom用此方法
/* protected override void DefWndProc(ref Message m)
{
switch (m.Msg)
{
case WM_COPYDATA:
COPYDATASTRUCT cdata = new COPYDATASTRUCT();
Type mytype = cdata.GetType();
cdata = (COPYDATASTRUCT)m.GetLParam(mytype);
this.textBox1.Text = cdata.lpData;
break;
default:
base.DefWndProc(ref m);
break;
}
} */
}
}

参考文档：

c# 进程间同步实现 进程之间通讯的几种方法