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IsNullCOMObject

See Also: FlexCOM Helper Functions, IsComObject, IsComObjectCreated, pvComObject

Purpose

Returns True if the passed variable or property is of type variant IDispatch* and is set to NULL. Returns False if the passed value is a non-NULL IDispatch* value.

Return Type

Boolean

Syntax

(IsNullComObject({vComObject}))

Parameters

  • vComObject: A value of type variant.

What it Does

This Boolean function returns True if the passed variable or property is of type variant IDispatch* and is set to NULL. It will return False if the passed value is a non-NULL IDispatch* value.

Use this function instead of attempting to use an IDispatch* variant in a comparative expression like (vComObject = 0). Such an expression would never work and would raise a runtime error.

Example

The following example tests a variant variable using IsNullComObject to see if it is a Null IDispatch*.

Variant vMyVar
// ...
If (Not(IsNullComObject(vMyVar))) Begin
    Move (NullComObject()) To vMyVar
End