The information in this article applies to:
- Microsoft Visual FoxPro for Windows, version 3.0
SYMPTOMS
When a DO FORM command is issued, the form is not displayed. The form is
never displayed, and no instance variable is created.
CAUSE
When a form created with the Form Designer is run, the instance is not
created under the following circumstances:
- The Init of the Form returns false (.F.).
-or-
- One of the object members of the form is not instantiated.
With the Visual FoxPro object model, all objects contained in a form are
created before the form is instantiated. The form is created if its
contained members have been successfully created. In particular, the Init
event of the form is triggered after the Init of all the controls it
contains. If the method associated with the Init event of any control in
the form returns false (.F.), the object member is not created and the form
in turn is not instantiated. If the object member is not created, the Init
of the form is not run, so the form is not created.
WORKAROUND
Ensure that all object members of a form are created before the form is
instantiated. For example, ensure that no Init method of a control returns
false (.F.) if you want to be able to create a form. You can use the
Visible and Enabled properties of a control to monitor its visibility and
accessibility.
STATUS
This behavior is by design.
MORE INFORMATION
Steps to Reproduce Behavior
- Create a form.
- Select the CommandButton control from the Form controls toolbar, and
place a command button on the form.
- In the property sheet, ensure that the Object is Command1, and select
the method for the Init event. Type the following:
Return cReturn
- Save the form.
- In the Command window, type cReturn= .t.
- Run the form. The form is displayed.
- In the Command window, type
CLEAR ALL
cReturn = .f.
- Run the form. because the command button is not created, the form is not
created.
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