Access a method from a DLL from C# program -

i have c program , have created dll file. using windows vista, , visual c++.

now need access method dll, main() method of c# code. steps of doing so?

so far have added dll file reference, thereafter should do?

this example:

int main1( void ) {   prinf("hello world"); } 

please note class makes of other .lib functions, able create dll out of it. (i don't know if relevant)

now need access method c# main();

[stathread] static void main() {   // need call main1() method here    application.enablevisualstyles();   application.setcompatibletextrenderingdefault(false);   application.run(new form1()); } 

see using class defined in c++ dll in c# code has great accepted answer. , hans passant wrote in comments, cannot add native dll reference c# project.

when refer 1 of own native dlls, either add dependency between c# project , project generates native dll, or add dll linked content file in c# project, so:

1. right-click on project , choose add > existing item.
2. browse , select dll want, don't click add yet.
3. click on tiny arrow @ right of add button , select add link.
4. select dll appears in c# project , go properties.
5. make sure have build action set content.

this copy dll bin\debug folder of c# project , make sure that, if once decide create setup project, can reference content files , include them in microsoft installer package.

now, able see functions written in native dll, have take care of exporting them (see exporting c functions use in c or c++ language executables , exporting dll using __declspec(dllexport)). you'd have add extern "c" block around function declaration (i assuming wrote code in .cpp source file , means compiler emit mangled function names if not declare them being extern "c"):

extern "c" {     __declspec (dllexport) void __cdecl foo(const char* arg1); }  ...  void foo(const char* arg1) {     printf ("hello %s !", arg1); } 

the __declspec (dllexport) decoration means compiler/linker have make function visible outside of dll. , __cdecl defines how parameters passed function (the standard "c" way of doing this).

in c# code, you'll have refer dll's exported methods:

class program {     [dllimport("mydll.dll")]     internal static extern void foo(string arg1);      static void main()     {         program.foo ("pierre");     } } 

you should read platform invoke tutorial gives gory details.