PRB: Error Message Accessing Objects Added to Visual FoxPro COM Server Objects (255725)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 6.0
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
Modification Type:MajorLast Reviewed:3/8/2000
Keywords:kbCodeSnippet kbCtrl kbDSupport kbprb KB255725
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