DllImport problems with c-style char arrays

[zubinr]

Hi guys,

I have function written in C

extern "C" __declspec(dllexport) char * receiveSTATUS()
{
....
....
}

that returns a pointer to a string of characters. This function is in a dll file (pfserver.dll) which i have imported into a C# .NET application using the DLL import attribute like...


[DllImport("pfserver.dll")]
public static extern string receiveSTATUS();

so i presume the c-style char array gets marshalled into a string in C#. The function is called in the C# app like...

string str = receiveSTATUS();

This method works for the most part but sometimes the string str (received in the C# app) has some garbage values in the beginnig few places e.g.

string to be returned "192.168.1.10|-"
string received "!,##!,#.1.10|-"

(the #'s are garbage characters that dont have a print representation and get printed as rectangles)

Most of the time this works... i.e I get the correct string back into the C# app but sometimes this weird garbage gets returned. I have no idea how to fix this. Maybe i need to do some marshalling using MarshalAs ?

Thanks for your help in advance

Z