Interop between C++ and C#

Question

I have this struct in C++:

struct TEXTMSGSTR
{
    HWND Sender;
    wchar_t Text[255];
    //wchar_t *Text;
};

and in C#:

public struct TEXTMSGSTR
{
    public IntPtr Sender;
    public ? Text;
}

which I am sending as part of a COPYDATASTRUCT message from unmanaged to managed code. What would be the correct construction of the struct on the C# side as C# does not have wchar_t? I have tried string etc. but of course errors appear!

Can anybody give me some ideas about how to marshal this as well as I am new to this stuff?:

TEXTMSGSTR tx = (TEXTMSGSTR)Marshal.PtrToStructure(cds.lpData, typeof(TEXTMSGSTR));

You should check out http://stackoverflow.com/questions/188299/marshal-c-struct-array-into-c All your answers are there. :) — Randolpho, May 19 '09 at 21:22
If you use just straight string without the marshalling part you get a memory corruption. — flavour404, May 19 '09 at 21:57

score 2 · Answer 1 · answered May 19 '09 at 21:24

2

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct TEXTMSGSTR
{
    public IntPtr Sender;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 255)]
    public string Text;
}

answered May 19 '09 at 21:24

Mehrdad Afshari

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Thanks Mehrdad, that worked great. I really need to read the articles on this, its not easy! Thanks. – flavour404 May 19 '09 at 21:55

score 0 · Answer 2 · edited May 23 '17 at 12:01

0

Try System.Runtime.InteropServices.UnmanagedType LPTStr or ByValTStr.

Also look at my answer to that question

edited May 23 '17 at 12:01

Community

1
1

answered May 19 '09 at 21:22

abatishchev

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I'll check out the link, I really need to understand this stuff. I'm fine with posting the messages its just when I get to the marshalling stuff I get really confused. Thanks. – flavour404 May 19 '09 at 21:57

Interop between C++ and C#

2 Answers2