Microsoft KB Archive/255725

Knowledge Base

PRB: Error Message Accessing Objects Added to Visual FoxPro COM Server Objects

Article ID: 255725

Article Last Modified on 3/8/2000

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APPLIES TO

• Microsoft Visual FoxPro 6.0 Professional Edition

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This article was previously published under Q255725

SYMPTOMS

If an object is added to a Component Object Model (COM) server at run time, attempts to access that object result in the following error message:

OLE error code 0x80020006: Unknown name

CAUSE

Visual FoxPro looks in the type library file (.tlb) to locate the object name reference associated with the COM server. When Visual FoxPro cannot find the object name reference there, it produces the error.

RESOLUTION

To resolve this situation, do one of the following:

Add a procedure or procedures to the COM server that can access the added object or objects.Utilize functions or procedures in lieu of adding objects to COM servers at run time.

STATUS

This behavior is by design.

MORE INFORMATION

To produce the behavior, perform the following steps:

1. Within Microsoft Visual FoxPro 6.0, create a new project called mytest.

2. Add a new program to the mytest project and input the following code:

   DEFINE CLASS myole AS CUSTOM OLEPUBLIC
       lcReturnValue = "This is a test."
       FUNCTION givereturn
           RETURN This.lcReturnValue
       ENDFUNC
       PROCEDURE returnmyname
             RETURN This.oMyName.lcMyName
       ENDPROC
   ENDDEFINE
   
   DEFINE CLASS myclass AS CUSTOM OLEPUBLIC
      lcMyName = "This is my name"
   ENDDEFINE
                       

3. Close and save the program as test.
4. In the Project Manager, click the Build button, and build a single-threaded COM server (DLL) in Visual FoxPro 6.0 with SP3, or build a COM DLL in Visual FoxPro 6.0. Upon completion of the build, close the Project Manager.

5. In the Microsoft Visual FoxPro Command window, run the following lines of code:

   oMyObj = CREATEOBJECT("mytest.myole") &&Loads the myole class of mytest.dll
   
   ?oMyObj.GiveReturn() &&This will print "This is a test." to the screen
   
   oMyObj.ADDOBJECT("oMyName","myclass") &&Add newclass object to myole
   
   ?oMyObj.oMyName.lcMyName  &&This will produce the error
                       

6. Use the following line of code in the Command window and confirm that the oMyNameobject is scoped to the returnmyname procedure:

   ?oMyObj.ReturnMyName()  &&This will print "This is my name" to the screen
                       

Keywords: kbcodesnippet kbprb kbctrl KB255725

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