Why Async Callback in System.Windows.Forms.Timer execute the await more times?-CodePudding

I have a windows forms timer with an async callback that await a database operation, why the await is executed again even before the previous callback has not finished yet? How can I fix this? Many people say that System.Windows.Forms.Timer wait that previous callback operation finishes before executing new one.

Private Async Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As  System.EventArgs) Handles Timer1.Tick 
  ' I have an array with 6 elements that i control 
  ' for executing database operation     
  For i=1 To 6
    If(some condition is true in array index)
      Await SaveAsync()
      'set to false the condition in array index after save
    End If
  Next       
End Sub

Thanks in advance.

CodePudding user response：

It is presumably because the asynchronous call takes longer than the Interval of your Timer. That would mean the Tick event would be raised again before the previous event handler has finished executing. If what you want is a specific interval between when the previous call has completed and the next event then you should stop the Timer, make the call and then start it again:

Private Async Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As  System.EventArgs) Handles Timer1.Tick 
    Timer1.Stop()
    Await SaveAsync()
    Timer1.Start()
End Sub