PRB: Object Variable Not Set Error If Object Not Instantiated

ID: Q129836

The information in this article applies to:

Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 16-bit and 32-bit, for Windows, version 4.0

SYMPTOMS

Referencing an object that has not been instantiated results in this error:

"Object variable or With block variable not Set"
(Err = 91)

CAUSE

If you declare an object as in this example:


   Dim MyForm as Form1

you have allocated a reference to the object (similar to a pointer in the C programming language), but you have not allocated or instantiated the object itself.

Therefore, when the object is referenced in code as in this example:


   MyForm.Print "Hello World!"

the error message "Object variable or With block not Set" is generated.

RESOLUTION

The following three code examples demonstrate how to declare and use an object variable (MyForm in this case) correctly:

Code Sample One


Dim MyForm as Form1
Set MyForm = New Form1
' Where the object type is the same as the object type used in the
' declaration.
MyForm.Print "Hello World!"

Code Sample Two


Dim MyForm as New Form1
MyForm.Print "Hello World!"

Code Sample Three


Dim MyForm as Form1
Dim MyForm1 as New Form1
Set MyForm= MyForm1
MyForm.Print "Hello World!"

Additional query words: 4.00 vb4win vb4all

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