DOCUMENT:Q141024 06-SEP-1996 [vbwin]
TITLE :How to Start a Visual Basic Screen Saver Using SendMessage API
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:4.00
OPER/SYS:WINDOWS
KEYWORDS:kbprg kbcode

------------------------------------------------------------------------
The information in this article applies to:

- Standard, Professional, and Enterprise Editions of Microsoft Visual
Basic, 16 and 32 bit, for Windows, version 4.0
------------------------------------------------------------------------

SUMMARY
=======

The sample code below shows how to start a Visual Basic screen saver
by sending a Windows message to the Control-menu box on a form.

MORE INFORMATION
================

Microsoft Windows starts screen savers through the System-menu box on
a form. The System-menu box is also known as the Control-menu box in
Visual Basic. You can send Windows messages to the Control-menu box
by using the SendMessage Windows API (application programming
interface) function.

[general declarations]

#If Win32 Then
Private Declare Function SendMessage Lib "user32" Alias _
"SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, _ ByVal wParam
As Long, ByVal lParam As Long) As Long

Const WM_SYSCOMMAND = &H112&
Const SC_SCREENSAVE = &HF140&
#Else
Private Declare Function SendMessage Lib "User" (ByVal _ hWnd
As Integer, ByVal wMsg As Integer, ByVal wParam As _ Integer,
lParam As Any) As Long

Const WM_SYSCOMMAND = &H112
Const SC_SCREENSAVE = &HF140&
#End If

Private Sub Command1_Click()
Dim result As Long
result = SendMessage(Form1.hWnd, WM_SYSCOMMAND, _
SC_SCREENSAVE, 0&)
End Sub

REFERENCES
==========

You can find two sample programs and a complete explanation showing how to
write your own screen savers in Visual Basic in the following book:

"Visual Basic Workshop 3.0" by John C. Craig, published by Microsoft Press.

Additional reference words: 3.00 4.00 vb4win vb4all .SCR TOPMOST
SETWINDOWPOS SCRNSAVE timer
KBCategory: kbprg kbcode
KBSubcategory: PrgCtrlsStd

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=

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