 As
with most of Windows' Ex-flavour APIs, FlashWindowEx provides extended
functionality over the older FlashWindow call. Through the FLASHWINFO
structure you can control the type of flashing :
-
"normal" mode, simulating FlashWindow's behaviour and requiring
an explicit command to stop (you call FlashWindowEx again with the
FLASHW_STOP message)
-
"by duration", where the window/taskbar flashes for a specific number
of times as indicated by the uCount parameter of FLASHWINFO at the
interval specified
-
"until activated", where the window continues flashing until it becomes
the active window.
In addition, each one of these modes provides for the flash-interval to
be specified, as well as specifying whether the flashing object should be
the on-screen window, the taskbar entry, or both. Like FlashWindow,
FlashWindowEx does not affect an applications icon that may reside in the
systray area of the taskbar; the code for animating the systray icon that
could be used in conjunction with FlashWindowEx is listed under the
Related items above.
Due to the number of options available, I chose to break up the visual
look of the demo form using frames. These are strictly for clarity and
serve no purpose to the actual demo of the routines. If you're interested
in replicating the above, Combo1 is at the top, Command1 and Command2 are
in frame 1, Command 3 and Combo2 are in frame 2, and Command 4 and Combo
3 are in frame 3.
When the Until Activated option is selected, the "Flashes until freeze"
value represents the number of flashes that will occur before the taskbar
item "stays on" (stops flashing in a highlighted state). I've
discovered that by passing -1, the flashing will continue until the
application is activated. At a value > 0, the item will flash and then
"freeze on".
Note as well that the demo builds a flag to demonstrate selectively flash
the window or the taskbar item. In practical use where you may want
to flash both, the provided constant FLASHW_ALL can be used in place of
FLASHW_FLAGS and/or FLASHW_CAPTION and FLASHW_TRAY. |
Option Explicit
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Copyright ©1996-2011 VBnet/Randy Birch, All Rights Reserved.
' Some pages may also contain other copyrights by the author.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Distribution: You can freely use this code in your own
' applications, but you may not reproduce
' or publish this code on any web site,
' online service, or distribute as source
' on any media without express permission.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'Stop flashing. The system restores the
'window to its original state
Private Const FLASHW_STOP As Long = 0
'Flash the window caption
Private Const FLASHW_CAPTION As Long = &H1
'Flash the taskbar button
Private Const FLASHW_TRAY As Long = &H2
'Flash both the window caption and taskbar button
Private Const FLASHW_ALL As Long = (FLASHW_CAPTION Or FLASHW_TRAY)
'Flash continuously, until the FLASHW_STOP flag is set
Private Const FLASHW_TIMER As Long = &H4
'Flash continuously until the window comes
'to the foreground
Private Const FLASHW_TIMERNOFG As Long = &HC
Private FLASHW_FLAGS As Long
Private Type FLASHWINFO
cbSize As Long
hwnd As Long
dwFlags As Long
uCount As Long
dwTimeout As Long
End Type
Private Declare Function FlashWindowEx Lib "user32" _
(pflashwininfo As FLASHWINFO) As Long
Private Sub Form_Load()
Dim cnt As Long
With Combo1
.AddItem "0 (default cursor rate)"
.AddItem "50"
.AddItem "100"
.AddItem "250"
.AddItem "500"
.AddItem "1000"
.ListIndex = 0
End With
With Combo2
For cnt = 5 To 100 Step 5
.AddItem cnt
Next
.ListIndex = 0
End With
With Combo3
.AddItem "-1"
.AddItem "0"
For cnt = 5 To 100 Step 5
.AddItem cnt
Next
.ListIndex = 0
End With
Command1.Caption = "Begin Flash"
Command2.Caption = "Stop Flash"
Command3.Caption = "Begin Flash"
Command4.Caption = "Begin Flash"
Check1.Caption = "Window"
Check2.Caption = "Tray"
Check1.Value = vbChecked
Check2.Value = vbChecked
End Sub
Private Sub Check1_Click()
FLASHW_FLAGS = 0&
If Check1.Value = vbChecked Then FLASHW_FLAGS = FLASHW_CAPTION
If Check2.Value = vbChecked Then FLASHW_FLAGS = FLASHW_FLAGS Or FLASHW_TRAY
End Sub
Private Sub Check2_Click()
FLASHW_FLAGS = 0&
If Check1.Value = vbChecked Then FLASHW_FLAGS = FLASHW_CAPTION
If Check2.Value = vbChecked Then FLASHW_FLAGS = FLASHW_FLAGS Or FLASHW_TRAY
End Sub
Private Sub Command1_Click()
Call FlashBegin(Me.hwnd, Val(Combo1.List(Combo1.ListIndex)))
Combo1.Enabled = False
Command1.Enabled = False
End Sub
Private Sub Command2_Click()
Call FlashEnd(Me.hwnd)
Command1.Enabled = True
Combo1.Enabled = True
End Sub
Private Sub Command3_Click()
Call FlashBeginCount(Me.hwnd, _
Val(Combo1.List(Combo1.ListIndex)), _
Val(Combo2.List(Combo2.ListIndex)))
End Sub
Private Sub Command4_Click()
Me.WindowState = vbMinimized
Call FlashBeginUntilActive(Me.hwnd, _
Val(Combo1.List(Combo1.ListIndex)), _
Val(Combo3.List(Combo3.ListIndex)))
End Sub
Private Sub FlashBegin(ByVal hwnd As Long, ByVal Frequency As Long)
Dim fwi As FLASHWINFO
With fwi
.cbSize = Len(fwi)
.hwnd = hwnd
.dwFlags = FLASHW_FLAGS Or FLASHW_TIMER
.dwTimeout = Frequency
.uCount = -1
End With
Call FlashWindowEx(fwi)
End Sub
Private Sub FlashBeginCount(ByVal hwnd As Long, _
ByVal Frequency As Long, _
ByVal nCount As Long)
Dim fwi As FLASHWINFO
If (nCount > 0) Then
With fwi
.cbSize = Len(fwi)
.hwnd = hwnd
.dwFlags = FLASHW_FLAGS
.dwTimeout = Frequency
.uCount = nCount
End With
Call FlashWindowEx(fwi)
End If
End Sub
Private Sub FlashBeginUntilActive(ByVal hwnd As Long, _
ByVal Frequency As Long, _
ByVal nCount As Long)
Dim fwi As FLASHWINFO
If (Frequency > 0) Then
With fwi
.cbSize = Len(fwi)
.hwnd = hwnd
.dwFlags = FLASHW_TIMERNOFG Or FLASHW_FLAGS
.dwTimeout = Frequency
.uCount = nCount
End With
Call FlashWindowEx(fwi)
End If
End Sub
Private Sub FlashEnd(ByVal hwnd As Long)
Dim fwi As FLASHWINFO
With fwi
.cbSize = Len(fwi)
.dwFlags = FLASHW_STOP
.hwnd = Me.hwnd
.uCount = 0
End With
Call FlashWindowEx(fwi)
End Sub |
