PRB: DO FORM Does Not Display a Form (132178)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 3.0
This article was previously published under Q132178

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

  1. Create a form.
  2. Select the CommandButton control from the Form controls toolbar, and place a command button on the form.
  3. In the property sheet, ensure that the Object is Command1, and select the method for the Init event. Type the following:

    Return cReturn

  4. Save the form.
  5. In the Command window, type cReturn= .t.
  6. Run the form. The form is displayed.
  7. In the Command window, type 
       CLEAR ALL
   cReturn = .f.
  8. Run the form. because the command button is not created, the form is not created.
Modification Type:MajorLast Reviewed:2/15/2000
Keywords:KB132178
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