C#中使用SendMessage进行进程通信,可以发送字符串。

/// <summary>

/// 定义结构体

/// </summary>

public struct COPYDATASTRUCT

{

public IntPtr dwData; //可以是任意值

public int cbData; //指定lpData内存区域的字节数

[MarshalAs(UnmanagedType.LPStr)]

public string lpData; //发送给目录窗口所在进程的数据

}

发送方：

[DllImport("User32.dll", EntryPoint = "SendMessage")]

private static extern int SendMessage(int hWnd, int Msg, int wParam, ref COPYDATASTRUCT lParam);

[DllImport("User32.dll", EntryPoint = "FindWindow")]

private static extern int FindWindow(string lpClassName, string lpWindowName);

const int WM_COPYDATA = 0x004A;//必须是这个数值，不能更改

private void btnSend_Click(object sender, EventArgs e)

{

int hWnd = FindWindow(null, @"消息接受者");

if (hWnd == 0)

{

MessageBox.Show("未找到消息接受者！");

}

else

{

string sendString = "测试发送数据";

byte[] sarr = System.Text.Encoding.Default.GetBytes(sendString);

int len = sarr.Length;

COPYDATASTRUCT cds;

cds.dwData = (IntPtr)0 ;

cds.cbData = len + 1;

cds.lpData = sendString;

SendMessage(hWnd, WM_COPYDATA, 0, ref cds);

}

}

接受方：

private static int WMA_InterPro = 0x004A;

protected override void DefWndProc(ref Message m)

{

if (m.Msg == WMA_InterPro)

{

COPYDATASTRUCT cds = new COPYDATASTRUCT();

Type t = cds.GetType();

cds = (COPYDATASTRUCT)m.GetLParam(t);

string
receiveInfo=cds.lpData;

}

else

{

base.DefWndProc(ref m);

}

}