PRB: "<XLL Name> Is Not a Valid Add-In" Error Message When You Load XLL That Is Rebuilt by Using Visual Studio .NET 2003 (824459)

WORKAROUND

1. Look at the beginning of your source file.
   
   The declaration of the array of static strings looks similar to the following code:

   #define g_rgWorksheetFuncsRows 4
   static char* g_rgWorksheetFuncs[g_rgWorksheetFuncsRows][10] =
   {
      { " TestArrayFunction",  // Procedure
         " BK",                // type_text
         " TestArrayFunction", // function_text
              ...
       }
   }
   

2. Rename the array to g_rgStaticWorksheetFuncs.
   
   This helps you by reducing the number of changes that you must make in the code of your XLL.

   #define g_rgWorksheetFuncsRows 4
   static char* g_rgStaticWorksheetFuncs[g_rgWorksheetFuncsRows][10] =
   {
      { " TestArrayFunction", // Procedure
         " BK",               // type_text
         " TestArrayFunction",// function_text
               ...
   
      }
   }
   

3. Add a new global variable with the same name as the original array name and with the same signature as the original array signature.
   
   Make sure that you do not initialize the new global variable with hard-coded values.

   #define g_rgWorksheetFuncsRows 4
   static char* g_rgWorksheetFuncs[g_rgWorksheetFuncsRows][10];
   static char* g_rgStaticWorksheetFuncs[g_rgWorksheetFuncsRows][10] =
   {
      { " TestArrayFunction",              // Procedure
         " BK",                                  // type_text
         " TestArrayFunction",              // function_text
               .
      }
   }
   

4. In the DllMain function of the XLL, verify that you have code that is similar to the following code.
   
   Note The purpose of this code is to length-prefix all the hard-coded strings.

      int i,j;
      for (i=0; i<g_rgWorksheetFuncsRows; i++) 
      {
         for (j=0; j<10; j++) 
         {
            BYTE currentVal = (BYTE)strlen(g_rgWorksheetFuncs[i][j]+1);
            g_rgWorksheetFuncs[i][j][0] = currentVal;
         }
      }
   

5. Rewrite the code in the DllMain function of the XLL so that the code is similar to the following code:
   
   Note The modified code copies the static string array to an array that is non-read-only. The modified code length-prefixes the copied non-read-only string for use by Excel.
   

     int i,j;
      for (i=0; i<g_rgWorksheetFuncsRows; i++) 
      {
         for (j=0; j<10; j++) 
         {
            //Get the current length of the static string.
            BYTE currentVal = (BYTE)strlen(g_rgStaticWorksheetFuncs[i][j]+1);
   
            //Create a new non-read-only string and then initialize it.
            g_rgWorksheetFuncs[i][j] = new char[currentVal+2];
            memset( g_rgWorksheetFuncs[i][j], '\0', currentVal+2 );
   
            //Copy the read-only string to the non-read-only string.
            memcpy( g_rgWorksheetFuncs[i][j]+1, g_rgStaticWorksheetFuncs[i][j] + 1,
               currentVal );
   
            //Length-prefix the non-read-only string.
            g_rgWorksheetFuncs[i][j][0] = currentVal;
         }
      }
   

6. Recompile and then test your XLL.