How to Create a Topmost or Floating Window in Visual Basic

ID: Q84251

The information in this article applies to:

SUMMARY

You can create a "floating" window such as that used for the Microsoft Windows version 3.1 Clock by using the SetWindowPos Windows API call.


MORE INFORMATION

A floating (or Topmost) window is a window that remains constantly above all other windows, even when it is not active. Examples of floating windows are the Find dialog box in WRITE.EXE, and CLOCK.EXE (when Always on Top is selected from the Control menu).

For more information on this topic, please see the following article in the Microsoft Knowledge Base:

Q81137 : INF: How to Create a Topmost Window


NOTE: Visual Basic forms that are TopMost Windows when they are in either Normal or Maximized positions will lose the Topmost setting when the Visual Basic program is Minimized. Visual Basic destroys the old window and creates a new one with the Icon in the Window. Therefore, in order for TopMost to stay in effect, the user needs to reset TopMost in the Resize event.

There are two methods to produce windows that "hover" or "float," one of which is possible in Visual Basic for Windows. This method is described below:

Use the following declarations: 

Declare Function SetWindowPos Lib "User" (ByVal hWnd As Integer, ByVal
hWndInsertAfter As Integer, ByVal X As Integer, ByVal Y As Integer, ByVal
cx As Integer, ByVal cy As Integer, ByVal wFlags As Integer) As Integer
' The above Declare statement must appear on one line.

Global Const SWP_NOMOVE = 2
Global Const SWP_NOSIZE = 1
Global Const FLAGS = SWP_NOMOVE Or SWP_NOSIZE
Global Const HWND_TOPMOST = -1
Global Const HWND_NOTOPMOST = -2
'Put global constants in bas module.

To set the form XXXX to TOPMOST, use the following code:

success% = SetWindowPos (XXXX.hWnd, HWND_TOPMOST, 0, 0, 0, 0, FLAGS) REM success% <> 0 When Successful

To reset the form XXXX to NON-TOPMOST, use the following code:

success% = SetWindowPos (XXXX.hWnd, HWND_NOTOPMOST, 0, 0, 0, 0, FLAGS) REM success% <> 0 When Successful

NOTE: This attribute was introduced in Windows, version 3.1, so remember to make a GetVersion() API call to determine whether the application is running under Windows, version 3.1.


REFERENCES

"Page 892 of Microsoft Windows 3.1 Programmer's Reference, Volume 2, Functions,"

Additional query words: top most Win31 Float Topmost Notopmost Setwindowpos 


Keywords          : kbcode kbWndw 
Version           : WINDOWS:1.0,2.0,3.0
Platform          : WINDOWS 
Issue type        :

Last Reviewed: May 12, 1999