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

ID: Q224397


The information in this article applies to:
  • Active Server Pages
  • Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0
  • Microsoft Internet Information Server versions 4.0, 5.0


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 kbGrpASP kbiis400 kbiis500
Version : WINDOWS:5.0,6.0; winnt:
Platform : WINDOWS winnt
Issue type : kbprb


Last Reviewed: December 8, 1999
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