C# 使用 SendMessage，WM_COPYDATA 有问题

Question

我已经花了几天(或更多)时间来尝试让它发挥作用。

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 发送请求到 FTPRush。

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

我的代码如下(使用的是SendMessage，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);

我还尝试了另一种规范:

[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，因为它有效:

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

哪个(我没有粘贴 dllimport，因为它在这里不重要。如果你想看，请告诉我)将窗口带到前面。另外，我通过调试 rush_cmdline.exe 进行了检查。所以句柄是一样的。

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可以工作，因为它与此非常匹配:perl example

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

我的定义有

[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);

当然要确保str是空终止的“\0”

或者由 PInvoke.NET 给出的定义是

[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.