FIX: Object Referenced by Property with ASSIGN Cannot Be Closed (314629)

SYMPTOMS

A form or other class is created with a custom property which has an associated ASSIGN method. When the class is instantiated, and a reference to another object is assigned to the custom property, you are unable to release the second object, even if the first object no longer exists.

RESOLUTION

To resolve this problem, obtain the latest service pack for Visual FoxPro for Windows 7.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

316964 How to Obtain the Latest Visual FoxPro for Windows 7.0 Service Pack

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Visual FoxPro for Windows 7.0 Service Pack 1.

MORE INFORMATION

Steps to Reproduce Behavior

Copy the following code to a new program and run it in Visual FoxPro 7.0:

LOCAL loMyForm AS FORM, ;
    loCustClass AS CUSTOM

loCustClass = CREATEOBJECT("MyCustom")
loMyForm = CREATEOBJECT("FORM")
loCustClass.ofrm = loMyForm
loMyForm.SHOW(1)

DEFINE CLASS MyCustom AS CUSTOM
	ofrm = .NULL.

	PROCEDURE ofrm_assign
		LPARAMETERS vNewVal
		THIS.ofrm = m.vNewVal
	ENDPROC
ENDDEFINE

When the form appears, try to close it by using the Close button; you are unable to do so. The only way to close the form is to issue a CLEAR ALL command from the Command Window.

NOTE: This problem only occurs if there is an ASSIGN method on the property holding the object reference ("ofrm_assign" in the example code).