C# 使用 SendMessage，WM_COPYDATA 问题

Question

我花了几天（或更长时间）试图让它发挥作用。

手头的应用程序是 FTPRush，我知道有一个名为 rush_cmdline.exe 的命令行应用程序，它使用 SendMessage 向 发送请求>FTPRush。

通过调试rush_cmdline.exe，我可以看到lParam、wParam、Message和hWnd。

我的代码如下（使用 SendMessage，而不是 SendMessageW）：

[DllImport("User32.dll", EntryPoint = "FindWindow")]
public static extern Int32 FindWindow(String lpClassName, String lpWindowName);
[DllImport("USER32.DLL", EntryPoint= "SendMessage")]
public static extern IntPtr SendMessage(int hWnd, int Msg, int wParam, IntPtr lParam);

我也尝试了另一个规范：

[DllImport("User32.dll", EntryPoint = "SendMessage")]
public static extern int SendMessage(int hWnd, int Msg, int wParam, ref COPYDATASTRUCT lParam);

句柄（hWnd）不是问题，因为这有效：

int ftprush = FindWindow("TfmRush", null);
ShowWindow(ftprush, 8);

哪个（我没有粘贴 dllimport，因为它在这里并不重要。如果您想查看它，请告诉我）将窗口置于前面。另外，我通过调试rush_cmdline.exe进行了检查。所以手柄是一样的。

两次尝试都失败了（默默地）：

public const Int32 WM_COPYDATA = 0x4A;
string msg = "RushApp.FTP.Login('backup','',0); ";
// 1
byte[] array = Encoding.UTF8.GetBytes((string)msg);
int size = Marshal.SizeOf(array[0]) * array.Length + Marshal.SizeOf(array[0]);
IntPtr ptr = Marshal.AllocHGlobal(size);
Marshal.Copy(array, 0, ptr, array.Length);
Marshal.WriteByte(ptr, size - 1, 0);
SendMessage(ftprush, WM_COPYDATA, 0, ptr);

// 2
public struct COPYDATASTRUCT
{
   public IntPtr dwData;
   public int cbData;
   [MarshalAs(UnmanagedType.LPStr)]
   public string lpData;
}

COPYDATASTRUCT cds;
cds.dwData = (IntPtr)100;
cds.lpData = msg;
cds.cbData = sarr.Length + 1;
SendMessage(ftprush, WM_COPYDATA, 0, ref cds);

我希望至少第二个解决方案能够工作，因为它与此非常匹配： perl 示例

非常感谢任何启发！

谢谢，

• 弗兰克

更新：

string msg = "RushApp.FTP.Login('backup','',0);\0";
var cds = new COPYDATASTRUCT
{
            dwData = new IntPtr(3),
            cbData = msg.Length + 1,
            lpData = msg
};
IntPtr ftprush = FindWindow("TfmRush", null);
SendMessage(ftprush, WM_COPYDATA, IntPtr.Zero, ref cds);

Answer 1

我的定义

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
public static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, ref COPYDATASTRUCT lParam);

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

var cds = new Win32.COPYDATASTRUCT {
                                           dwData = new IntPtr(3),
                                           cbData = str.Length + 1,
                                           lpData = str
                                         };
Win32.SendMessage(ftprush, Win32.WM_COPYDATA, IntPtr.Zero, ref cds);

当然，请确保 str 以 null 结尾“\0”

或者由 PInvoke 给出的定义。 NET 是

[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, StringBuilder lParam);
//If you use '[Out] StringBuilder', initialize the string builder with proper length first.

Answer 2

在上面的两个答案之间，我拼凑了一个工作示例。 Bryce Wagner 的类有效，因此我添加了一个方法来使用 SendMessageTimeout 发送数据。它是一个静态方法，因此您只需调用它来发送数据即可。这实际上不是我的工作，只是粘合在一起并分享回来。

    [StructLayout(LayoutKind.Sequential)]
    public struct CopyData: IDisposable {
        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
        static extern IntPtr SendMessageTimeout(IntPtr hWnd, uint Msg, IntPtr wParam, ref CopyData target,
                                                SendMessageTimeoutFlags fuFlags, uint uTimeout, out UIntPtr lpdwResult);

        [Flags]
        enum SendMessageTimeoutFlags: uint {
            SMTO_NORMAL             = 0x0,
            SMTO_BLOCK              = 0x1,
            SMTO_ABORTIFHUNG        = 0x2,
            SMTO_NOTIMEOUTIFNOTHUNG = 0x8
        }
        const uint WM_COPYDATA = 0x4A;

        public IntPtr dwData;
        public int cbData;
        public IntPtr lpData;

        public void Dispose() {
            if (lpData != IntPtr.Zero) {
                Marshal.FreeCoTaskMem(lpData);
                lpData = IntPtr.Zero;
                cbData = 0;
            }
        }
        public string AsAnsiString {
            get { return Marshal.PtrToStringAnsi(lpData, cbData); }
        }
        public string AsUnicodeString {
            get { return Marshal.PtrToStringUni(lpData); }
        }
        public static CopyData CreateForString(int dwData, string value, bool Unicode = false) {
            var result = new CopyData();
            result.dwData = (IntPtr) dwData;
            result.lpData = Unicode ? Marshal.StringToCoTaskMemUni(value) : Marshal.StringToCoTaskMemAnsi(value);
            result.cbData = value.Length + 1;
            return result;
        }

        public static UIntPtr Send(IntPtr targetHandle, int dwData, string value, uint timeoutMs = 1000, bool Unicode = false) {
            var cds = CopyData.CreateForString(dwData, value, Unicode);
            UIntPtr result;
            SendMessageTimeout(targetHandle, WM_COPYDATA, IntPtr.Zero, ref cds, SendMessageTimeoutFlags.SMTO_NORMAL, timeoutMs, out result);
            cds.Dispose();
            return result;
        }
    }

使用方法：

CopyData.Send(targetHandle, 1234, "This is a test");

使用默认的 1 秒超时。

Answer 3

COPYDATASTRUCT 中参数的顺序至关重要，而 Bob Vale 的回答却将它们的顺序弄错了。 http://msdn.microsoft。 com/en-us/library/windows/desktop/ms649010(v=vs.85).aspx 应该按这个顺序：

[StructLayout(LayoutKind.Sequential)]
public struct COPYDATASTRUCT
{
    public IntPtr dwData;
    public int cbData;
    public IntPtr lpData;
}

我还没有得到MarshalAs(UnmanagedType.LPStr)] public string lpData 可以工作。我只是通过自己进行编组才使其工作：

[StructLayout(LayoutKind.Sequential)]
public struct COPYDATASTRUCT : IDisposable
{
    public IntPtr dwData;
    public int cbData;
    public IntPtr lpData;

    /// <summary>
    /// Only dispose COPYDATASTRUCT if you were the one who allocated it
    /// </summary>
    public void Dispose()
    {
        if (lpData != IntPtr.Zero)
        {
            Marshal.FreeCoTaskMem(lpData);
            lpData = IntPtr.Zero;
            cbData = 0;
        }
    }
    public string AsAnsiString { get { return Marshal.PtrToStringAnsi(lpData, cbData); } }
    public string AsUnicodeString { get { return Marshal.PtrToStringUni(lpData); } }
    public static COPYDATASTRUCT CreateForString(int dwData, string value, bool Unicode = false)
    {
        var result = new COPYDATASTRUCT();
        result.dwData = (IntPtr)dwData;
        result.lpData = Unicode ? Marshal.StringToCoTaskMemUni(value) : Marshal.StringToCoTaskMemAnsi(value);
        result.cbData = value.Length + 1;
        return result;
    }
}