PRB: Cannot Find Entry Point (DLL Name) in the DLL

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b

SYMPTOMS

When you declare a Win32 DLL, the following error occurs:

   Cannot find entry point Mydll in the DLL

CAUSE

This error occurs because all 32-Bit DLL procedure names are case sensitive.

RESOLUTION

To avoid this error, copy the function name, description, and parameters from the Win32 API function Help file into your Visual FoxPro program file. This documents the function in your code and ensures that the correct case is used.

For example, the GetUserName function retrieves the name of the user currently logged onto the system:

   BOOL GetUserName(

      LPTSTR  lpBuffer,// address of name buffer
      LPDWORD  nSize // address of size of name buffer
     );
   Parameters

The nSize parameter points to a DWORD that, on input, specifies the maximum size, in characters, of the buffer specified by the lpBuffer parameter. If this buffer is not large enough to contain the entire user name, the function fails. If the function succeeds, it will place the number of characters copied to the buffer into the DWORD to which nSize points.

To call the GetUserName DLL in Visual FoxPro, use this command:

   DECLARE GetUserName in Win32API ;
      String @mybuffer, Integer @mybuffersize

   DECLARE GetuserName in Win32API ;
      String @mybuffer, Integer @mybuffersize

   Cannot find entry point GetuserName in the DLL.

STATUS

This behavior is by design.