One Shot Timers
in [Visual Basic]
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From: Karl E. Peterson on 30 Jun 2010 17:15 Jim Mack submitted this idea : > Karl E. Peterson wrote: >> Brain freeze here, I guess. >> >> I need a simple one-shot timer (non form-based). I was thinking, >> just use SetTimer, then call KillTimer in the callback. But, >> KillTimer fails in the callback. LastDllError=0. >> >> What quick/easy way am I forgetting for a one-shot deal like this? >> (Betting I need to go with mmTimers, but I've been staring at the >> screen for too long, and need to stretch...) > > Of course, with an mmTimer, you can just create a one-shot and be > done. That's what I'm thinking too. About as clean as it gets. -- ..NET: It's About Trust! http://vfred.mvps.org
From: Karl E. Peterson on 30 Jun 2010 17:16 Bob Butler pretended : > "Karl E. Peterson" <karl(a)exmvps.org> wrote... >> Brain freeze here, I guess. >> >> I need a simple one-shot timer (non form-based). I was thinking, just use >> SetTimer, then call KillTimer in the callback. But, KillTimer fails in the >> callback. LastDllError=0. > > works for me; what makes you think it is failing? KillTimer return value 0 > is error, non-zero is success Retval is 0. Timer keeps firing. > Private Declare Function KillTimer Lib "user32" (ByVal hwnd As Long, _ > ByVal nIDEvent As Long) As Long > Private Declare Function SetTimer Lib "user32" (ByVal hwnd As Long, _ > ByVal nIDEvent As Long, ByVal uElapse As Long, _ > ByVal lpTimerFunc As Long) As Long > > Public Sub StartTimer(ByVal hwnd As Long) > Dim x As Long > x = SetTimer(hwnd, 1, 2000, AddressOf TimerFunc) > Debug.Print "Start", x, Err.LastDllError > End Sub > > Private Sub TimerFunc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal idEvent > As Long, ByVal dwTime As Long) > Dim x As Long > Static k As Long > k = k + 1 > If k = 5 Then > x = KillTimer(hwnd, idEvent) > Debug.Print "Stop", x, Err.LastDllError > Else > Debug.Print "Fire" > End If > End Sub Hmmmm, that gives me a thought... -- ..NET: It's About Trust! http://vfred.mvps.org
From: Nobody on 30 Jun 2010 17:17 "Karl E. Peterson" <karl(a)exmvps.org> wrote in message news:i0gar1$ooe$1(a)news.eternal-september.org... > Brain freeze here, I guess. > > I need a simple one-shot timer (non form-based). I was thinking, just use > SetTimer, then call KillTimer in the callback. But, KillTimer fails in > the callback. LastDllError=0. > > What quick/easy way am I forgetting for a one-shot deal like this? > (Betting I need to go with mmTimers, but I've been staring at the screen > for too long, and need to stretch...) You probably didn't use the return value of SetTimer, but I could be mistaken. Here is an example to try. Post the code in Module1, and remove Form1 from a new project. Option Explicit Public Declare Function SetTimer Lib "user32" (ByVal hwnd As Long, _ ByVal nIDEvent As Long, ByVal uElapse As Long, _ ByVal lpTimerFunc As Long) As Long Public Declare Function KillTimer Lib "user32" (ByVal hwnd As Long, _ ByVal nIDEvent As Long) As Long Public Const WM_TIMER = &H113 Public TimerID As Long Public Done As Boolean Public Sub Main() Done = False TimerID = SetTimer(0, 0, 5000, AddressOf TimerProc) Debug.Print "SetTimer returned " & TimerID & ", LastDllError = " & _ Err.LastDllError Do While Not Done DoEvents Loop End Sub Public Sub TimerProc(ByVal hwnd As Long, ByVal uMsg As Long, _ ByVal idEvent As Long, ByVal dwTime As Long) Dim ret As Long Debug.Print "Timer" ret = KillTimer(0, TimerID) Debug.Print "KillTimer returned " & ret & ", LastDllError = " & _ Err.LastDllError Done = True End Sub Output(In the IDE using VB6+SP5 on XP+SP2): SetTimer returned 22353, LastDllError = 0 Timer KillTimer returned 1, LastDllError = 0
From: Jim Mack on 30 Jun 2010 17:21 Karl E. Peterson wrote: > Jim Mack submitted this idea : >> Karl E. Peterson wrote: >>> Brain freeze here, I guess. >>> >>> I need a simple one-shot timer (non form-based). I was thinking, >>> just use SetTimer, then call KillTimer in the callback. But, >>> KillTimer fails in the callback. LastDllError=0. >>> >>> What quick/easy way am I forgetting for a one-shot deal like this? >>> (Betting I need to go with mmTimers, but I've been staring at the >>> screen for too long, and need to stretch...) >> >> Of course, with an mmTimer, you can just create a one-shot and be >> done. > > That's what I'm thinking too. About as clean as it gets. Clean except you can't do any real work in the callback, so you end up complicating it again with a flag or a message... -- Jim
From: Karl E. Peterson on 30 Jun 2010 17:23
Jim Mack laid this down on his screen : > Karl E. Peterson wrote: >> Jim Mack submitted this idea : >>> Karl E. Peterson wrote: >>>> Brain freeze here, I guess. >>>> >>>> I need a simple one-shot timer (non form-based). I was thinking, >>>> just use SetTimer, then call KillTimer in the callback. But, >>>> KillTimer fails in the callback. LastDllError=0. >>>> >>>> What quick/easy way am I forgetting for a one-shot deal like this? >>>> (Betting I need to go with mmTimers, but I've been staring at the >>>> screen for too long, and need to stretch...) >>> >>> Of course, with an mmTimer, you can just create a one-shot and be >>> done. >> >> That's what I'm thinking too. About as clean as it gets. > > Clean except you can't do any real work in the callback, so you end up > complicating it again with a flag or a message... True. Solved it, though, at Bob's instigation. Remember I said it was already pretty complex? D'oh! Had the wrong hWnd in the kill call. Time for nice *long* break... :-S -- ..NET: It's About Trust! http://vfred.mvps.org |