Question

C function pointers to C# delegates

Asked by: thearty

Can someone please tell me how I can call a function from a C dll in C# using delegates?

i.e. I want to change this (C)...

typedef long (*InitializePluginProc)(void **userData);

typedef      struct _PluginInterface
{
     InitializePluginProc      initializePlugin;
     .............
}PluginInterface, FAR *LPPluginInterface;


to the equivalent in C# (This is what I have so far!)...

public unsafe delegate int  *InitializePluginProc(void **userData);

public unsafe struct PluginInterface
{
     public InitializePluginProc *initializePlugin;
     ......
     ......
}

in main()...

     intf = (PluginInterface)Marshal.PtrToStructure(handle,typeof(PluginInterface));

     //int err = (int)(*(intf.initializePlugin))(&userData); // How do I do this???


Cheers guys! T.

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Asked On
2005-09-26 at 03:32:35ID21573876
Tags

pointer

Topic

C# Programming Language

Participating Experts
1
Points
500
Comments
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Answers

 

by: LinuxBugsPosted on 2005-09-27 at 01:18:33ID: 14964964

 

by: LinuxBugsPosted on 2005-09-27 at 02:16:22ID: 14965125

 

by: LinuxBugsPosted on 2005-09-27 at 02:25:41ID: 14965151

in main()...

     intf = (PluginInterface)Marshal.PtrToStructure(handle,typeof(PluginInterface));
     void *temp = userData
     int err = intf.initializePlugin(&temp);


try this out. i guess this will work

 

by: theartyPosted on 2005-09-27 at 04:49:51ID: 14965651

LinuxBugs, I haven't looked at you links yet (will do tomorrow thank you) but when I try the above function call I get the following error...

An unhandled exception of type 'System.NullReferenceException' occurred in DRA1PluginTestingTony.exe

Additional information: Object reference not set to an instance of an object.

I think my problems are bigger. If you can check this site and see if you can clear up anything for me!

http://www.codeproject.com/useritems/Cdecl_CSharp_VB.asp?print=true

Again many thanks!!! T.

 

by: LinuxBugsPosted on 2005-10-06 at 22:11:53ID: 15036224

from what I have understood, I think we cant don anything with the function pointer which we get beacause it points to a funtion that is not present in the present existing file. may be we can use it if we try and duplicate the C function in C#

sorry for the late response but I was busy for the past few days :)

20120131-EE-VQP-002

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