Difference between revisions of "RPC HELP DLL GuideLines C Initialize LoadLibrary GetProcAddress"

Latest revision as of 16:28, 8 July 2015

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C: Initialize -- LoadLibrary and GetProcAddress

The first step to using the RPC Broker 32-bit DLL in a C program is to load the DLL and get the process addresses for the exported functions.

To initialize access to the Broker DLL functions:

1. Use the Windows API LoadLibrary function to load the DLL.

   HINSTANCE hLib = LoadLibrary("bapi32.dll");
   if((unsigned)hLib<=HINSTANCE_ERROR)
   {
     /* Add your error handler for case where library fails to load. */
     return 1;
   }

2. If you successfully load the DLL, map function pointers to the addresses of the functions in the DLL that you need for your application:

   RPCBCreate = (void *(__stdcall*)()) GetProcAddress(hLib, "RPCBCreate");
   RPCBFree = (void (__stdcall*)(void *)) GetProcAddress(hLib, "RPCBFree");
   RPCBCall = (char *(__stdcall*)(void *, char *)) GetProcAddress(hLib, "RPCBCall");
   RPCBCreateContext = (bool (__stdcall*)(void *, char *)) GetProcAddress(hLib, "RPCBCreateContext");
   RPCBMultSet = (void (__stdcall*)(void *, int, char *, char *)) GetProcAddress(hLib, "RPCBMultSet");
   RPCBParamGet = (void (__stdcall*)(void *, int, int, char *)) GetProcAddress(hLib, "RPCBParamGet");
   RPCBParamSet = (void (__stdcall*)(void *, int, int, char *)) GetProcAddress(hLib, "RPCBParamSet");
   RPCBPropGet = (void (__stdcall*)(void *, char *, char *)) GetProcAddress(hLib, "RPCBPropGet");
   RPCBPropSet =(void (__stdcall*)(void *, char *, char *)) GetProcAddress(hLib, "RPCBPropSet");
   //
   // GetProcAddress, returns null on failure.
   //
   if( RPCBCreate == NULL || RPCBFree == NULL || RPCBCall == NULL || RPCBCreateContext == NULL
   || RPCBMultSet == NULL || RPCBParamGet == NULL || RPCBParamSet == NULL || RPCBPropGet == NULL
   || RPCBPropSet == NULL)
   {
     /* Add your error handler for cases where functions are not found. */
     return 1;
   }

Now you can use functions exported in the DLL.