Q129413: Explanation & Usage of the LOCKSCREEN Property

Article: Q129413
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0
Operating System(s): 
Keyword(s): 
Last Modified: 12-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SUMMARY
=======

Visual FoxPro forms support a special form property called LOCKSCREEN. This
property is used to govern the behavior of a screen including how and when it
updates when an event such as a color change occurs.

MORE INFORMATION
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The LOCKSCREEN property is explained as follows in the online Help:

  The LOCKSCREEN property determines whether a Form batches all changes to
  property settings on the Form and its contained objects.

  Syntax:

  Form.LockScreen[ = lExpr]

  Settings:

  lExpr

  The settings for the LockScreen property are:

  Setting      Description
  --------------------------------------------------------------------
  True (.T.)   The Form and its contained objects reflect changes in
               property settings in batch mode, or all at once, rather
               than as soon as the changes are made.

  False (.F.)  (Default) The Form and its contained objects reflect
               changes in property settings as soon as the changes are
               made.

  Remarks:

  Available at design time and run time.

  Set LockScreen to true (.T.) to reduce annoying screen refreshes when
  presentation properties such as BackColor, FontName, and so on are changed
  during run time.

  NOTE: If you set LockScreen to false (.F.), the Form and all its controls are
  repainted.

The LOCKSCREEN property is found on the Layout tab of the Form Properties sheet.
As noted, the default for this property is false, which means that as soon as a
change is made to a form or its objects, as in the following, the change will be
immediately reflected on the form:

  Form1.BackColor=RGB(150,0,200)

If the LOCKSCREEN property is set to true, the previous command will not be
reflected until such time as you issue a command like this:

  FORM1.REFRESH

-or-

  FORM1.PAINT

The key advantage to you as a programmer is that you can make a series of changes
to an object such as a screen without having each item flicker and update to
reflect the new changes you've made. Instead, you can turn this property off,
make your changes, and then force a refresh of the screen for a much crisper and
more professional appearance.

Additional query words: VFoxWin Screen Update Refresh 3.00

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : WINDOWS:3.0

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