c# – 调用SendMessage(P / Invoke)不断崩溃

2023年3月31日 261次阅读

我不得不写一个与第三方程序通信的应用程序(
AOL,对不起.:()

做了大量的研究我发现了一些方法可以用P/Invoke做到这一点,并且在大多数情况下它可以正常工作,但它会在随后的试验中崩溃,特别是SendMessage.我正在概述下面的崩溃代码.

所有这些都是从旧的Visual Basic文件移植到.NET.它本来是古老的,我理解它是不可行的 – 我只是希望有一种比Visual Basic 4.0更好的方法来完成这项工作.

[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool CloseHandle(IntPtr hObject);

[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr hwndParent,
                                         IntPtr hwndChildAfter,
                                         string lpszClass,
                                         string lpszWindow);

[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr parentHandle,
                                         IntPtr childAfter,
                                         string className,
                                         IntPtr windowTitle);

[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr SendMessage(HandleRef hWnd,
                                        UInt32 Msg,
                                        IntPtr wParam,
                                        IntPtr lParam);

[DllImport("user32.dll", EntryPoint="SendMessageW")]
public static extern IntPtr SendMessageByString(HandleRef hWnd,
                                                UInt32 Msg,
                                                IntPtr wParam,
                                                StringBuilder lParam);

[DllImport("user32.dll", CharSet = CharSet.Unicode , EntryPoint = "SendMessageW")]
public static extern IntPtr SendMessageByString(HandleRef hWnd,
                                                UInt32 Msg,
                                                IntPtr wParam,
                                                String lParam);

public IntPtr FindClientWindow()
{
    IntPtr aol = IntPtr.Zero;
    IntPtr mdi = IntPtr.Zero;
    IntPtr child = IntPtr.Zero;
    IntPtr rich = IntPtr.Zero;
    IntPtr aollist = IntPtr.Zero;
    IntPtr aolicon = IntPtr.Zero;
    IntPtr aolstatic = IntPtr.Zero;

    aol = Invoke.FindWindow("AOL Frame25", null);
    mdi = Invoke.FindWindowEx(aol, IntPtr.Zero, "MDIClient", null);
    child = Invoke.FindWindowEx(mdi, IntPtr.Zero, "AOL Child", null);
    rich = Invoke.FindWindowEx(child, IntPtr.Zero, "RICHCNTL", null);
    aollist = Invoke.FindWindowEx(child, IntPtr.Zero, "_AOL_Listbox", null);
    aolicon = Invoke.FindWindowEx(child, IntPtr.Zero, "_AOL_Icon", null);
    aolstatic = Invoke.FindWindowEx(child, IntPtr.Zero, "_AOL_Static", null);

    if (rich != IntPtr.Zero &&
        aollist != IntPtr.Zero &&
        aolicon != IntPtr.Zero &&
        aolstatic != IntPtr.Zero)

        return child;
    do
    {
        child = Invoke.FindWindowEx(mdi, child, "AOL Child", null);
        rich = Invoke.FindWindowEx(child, IntPtr.Zero, "RICHCNTL", null);
        aollist = Invoke.FindWindowEx(child, IntPtr.Zero, "_AOL_Listbox", null);
        aolicon = Invoke.FindWindowEx(child, IntPtr.Zero, "_AOL_Icon", null);
        aolstatic = Invoke.FindWindowEx(child, IntPtr.Zero, "_AOL_Static", null);

        if (rich != IntPtr.Zero &&
            aollist != IntPtr.Zero &&
            aolicon != IntPtr.Zero &&
            aolstatic != IntPtr.Zero)

            return child;
    }
    while (child != IntPtr.Zero)
        ;

    return child;
}

IntPtr room = IntPtr.Zero;
IntPtr child = IntPtr.Zero;
IntPtr length = IntPtr.Zero;
IntPtr roomHandle = IntPtr.Zero;

child = FindClientWindow();
room = FindChildByClass(child, "RICHCNTLREADONLY");

HandleRef n = new HandleRef(IntPtr.Zero, room);

length = SendMessage(n, 0x000E, IntPtr.Zero, IntPtr.Zero);

// This is the line that keeps crashing on me.
SendMessageByString(n, 0x000D, new IntPtr( length.ToInt32() + 1 ), str);

public IntPtr FindChildByClass(IntPtr parent, string child)
{
    return Invoke.FindWindowEx(parent, IntPtr.Zero, child, null);
}

最佳答案 你正在使用宽字节SendMessage..ie广泛字符,你尝试过正常的Sendmessage ..

public static extern int SendMessage(IntPtr hWnd,UInt32 Msg,Int32 wParam,Int32 lParam);

我也注意到它就好像你试图根据richtextbox控件的句柄改变值,因此在另一个进程中寻找AOL的客户端窗口……这是正确的吗？

这可能是问题的根源,直接修改属于不属于您的窗口的控件(您的程序被管理,修改非托管进程的窗口)……这可以解释它崩溃的原因.你能澄清什么是十六进制常数吗？

编辑：当您使用WM_GETTEXTLENGTH和WM_GETTEXT时,它们是Windows消息的一部分,用于从控件中检索文本长度和实际文本.如果你看here并看看pinvoke.net对它们有什么看法……当你用WM_GETTEXTLENGTH和WM_GETTEXT发出’SendMessage’时,你告诉Windows – ‘嘿,告诉我相关句柄中文本的长度我已经在参数n中给你了.刚发生在我身上,值得一试…我会摆脱那些SendMessage pinvokes并使用这一个..

[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.


child = FindClientWindow();
room = FindChildByClass(child, "RICHCNTLREADONLY");

length = SendMessage(n, 0x000E, IntPtr.Zero, IntPtr.Zero);

StringBuilder sbBuf = new StringBuilder(length);

SendMessageByString(room, 0x000D, new IntPtr( length.ToInt32() + 1 ), out sbBuf); // this is the line that keeps crashing on me.

试试看,回到这里…… 🙂

希望这可以帮助,
最好的祝福,
汤姆.

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