PRB: "Error Loading DLL" When Returning User Defined Data Type from VB COM Object

• Active Server Pages
• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SYMPTOMS

When returning an Array or Collection of user defined data types (UDTs) from a Visual Basic COM object to Active Server Pages (ASP), the following error may occur:

Microsoft VBScript runtime error '800a0030'
Error Loading DLL: TestMethod

CAUSE

User defined data types are not supported in the current version of ASP.

RESOLUTION

Since ASP does not support UDTs, you can work around this by creating a new class to handle the data in place of the UDT and setting the instancing property to PublicNotCreateable. This will ensure that you can pass the necessary information to and from ASP, as well as that the class cannot be created outside of the DLL.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a Visual Basic ActiveX DLL Project called "VBUDTPrj."



2. Add class module called "VBUDTObj."



3. Define a user defined data type as follows:

        
   Public Type TestUDT
      strName as String
      strDept as String  
   End Type 




4. Implement the following method:

   
   Public Function TestMethod()As Variant
     Dim rtnArray(10) As Variant
     Dim intCnt As Integer
     For intCnt = 0 To 9
       Dim udtTestData As TestUDT
       udtTestData.strName = "Name"
       udtTestData.strDept = "Department"
       rtnArray(intCnt) = udtTestData
     Next
     TestMethod = rtnArray
   End Function 




5. Create an ASP Page that calls this Method:

   
     <%
       Dim objTest, udtArray, udtData
       Set objTest = Server.CreateObject("VBUDTPrj.VBUDTObj")
       udtArray = objTest.TestMethod()
       udtData = udtArray(1)  
       Response.Write( "Name = " & udtData.strName & "<BR>" )
       Response.Write( "Dept = " & udtData.strDept & "<BR>" )
     %> 




6. Run the ASP page and the following error occurs:

   Microsoft VBScript runtime error '800a0030'
   Error Loading DLL: TestMethod
   

REFERENCES

Refer to the TYPE statement in the Visual Basic Documentation.

Additional query words:

Keywords          : kberrmsg kbASP kbASP400 kbCOMt kbVBp500 kbVBp600 kbVBScript100 kbGrpASP 
Version           : WINDOWS:5.0,6.0; winnt:
Platform          : WINDOWS winnt 
Issue type        : kbprb 

Last Reviewed: May 25, 1999