[RESOLVED] Pause in a loop

[flickflucker]

I am extreemly new at this, but my tutors couldnt help either

I am using VB6

I am using a for-next and want to pause inbetween each go but cant work out how

for a=10 to 300 step 10
line(a,100)-(a-400)
next a

I want a pause inbetween drawing each line
I have tried sleep or putting a for-next loop to slow it down but I cant get it to work properly

Any help would be nice

Thanks

Ady

[danecook21]

The better way to accomplish this, then, would probably be a Timer control. That way you are running the code at a set interval, instead of looping but then having to slow it down.

[isnoend07]

you could use a timer

'=======in decalartion area
Dim Frequency As Long
'=======form load
Private Sub Form_Load()
Timer1.Interval = 60000
Frequency = 1
End Sub

'========timer event
Private Sub Timer1_Timer()
If Frequency = 15 Then
    'do your staff
    Frequency = 0
end if
Frequency = Frequency + 1
End Sub

Change the interval and frequency to what you want

[tropix100]

For a = 10 To 300 Step 10
    Line (a, 100)-(a, 400)
    For I = 0 To 50000
        DoEvents
    Next I
Next a

[danecook21]

tropix.... that is not a good thing to do... at all. DoEvents is a command to make sure windows can process things so things won't freeze up... Calling that fifty thousand times in a row will pretty much defeat the purpose. He said he wanted a pause in between line draws and the appropriate answer has been given... twice in fact.

[tropix100]

danecook..... I totally agree with what you have said here. the purpose of the doevents is to enable the same escape from the loop if needed. This would not be a normal call to use in a more complex program which was performing other functions and or sub routines. In such a small proceure, it is quite acceptable.
As an experienced programmer as yourself you will be well aware that there is never a right or wrong way to get there....only a more or less efficient.

[danecook21]

I don't know if I agree with that last statement but if so, that way is so inefficient it could be called wrong I mean it is literally just wasting away CPU time. If the task you're doing requires that, you need to rethink your logic.

[Pradeep1210]

I don't know if I agree with that last statement but if so, that way is so inefficient it could be called wrong I mean it is literally just wasting away CPU time. If the task you're doing requires that, you need to rethink your logic.

I'm not sure, but the timer control internally just keeps looping same as the code above. How else could it know that it's time for next iteration to begin?

Pradeep

[si_the_geek]

The timer control does not loop like that - if you compile 2 programs (one with a loop, and one with a timer), you will see that the one with the timer uses much less CPU time than the loop equivalent.

I don't really know what methods the timer uses, but suspect it is using some kind of API timer (which is fired by Windows at the apt time, as part of its other work).

[flickflucker]

ok thanks all for your answers.

Only thing is when I said I am new I mean really new. The only reason VB was introduced to our lesson was to illistrate algebra.
The only commands we were shown was line, for next and step.

I have been playing (basically trying to use my old zx spectrum basic)
and have now made lots of pretty paterns.

Now I am trying to make my patterns appear gradually rather than just popping up finished.
So what I am really asking is could someone please just show me the code from top to bottom for the simple loop I put at the begining so I could just copy and paste it onto form1 and it run. That way I could understand it better then I could adapt it to fit into my pattern.

Thanks in advance

Ady

[CDRIVE]

Here's some code that you can copy & paste. One procedure uses a For Next loop with a Pause statement in it. The Pause statement calls the Pause Sub on each loop. When the loop is exited it fires the timer that repeats the action without a loop. This time the timer code moves the Line. Basically, these two procedures demonstrate two ways of doing the same thing.
Put a Timer, CommandButton and two Line Controls on your form. Then copy and paste this code. Note how the Pause Sub is used here. This is an extremely versatile sub and is definitely one of my favorites.

Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Form_Load()
   Me.WindowState = vbMaximized
   Timer1.Enabled = False
End Sub

Private Sub Command1_Click()
   Static i As Integer
   For i = 1 To 5000 Step 10
     ' DoEvents
      i = i + 1
         Line1.X2 = i + 1000
         Line1.X1 = i + 1000
      Pause 0.01                          ' Pause 10 milliseconds
      Show
   Next
   Timer1.Enabled = True
   Timer1.Interval = 10                ' Timer Interval is 10 milliseconds.
End Sub

' Credits: (Milk (Sleep+Pause Sub)). (Wayne Spangler (Pause Sub))
Private Sub Pause(ByVal Delay As Single)
   Delay = Timer + Delay
   If Delay > 86400 Then 'more than number of seconds in a day
      Delay = Delay - 86400
      Do
          DoEvents ' to process events.
          Sleep 1 ' to not eat cpu
      Loop Until Timer < 1
   End If
   Do
       DoEvents ' to process events.
       Sleep 1 ' to not eat cpu
   Loop While Delay > Timer
End Sub

Private Sub Timer1_Timer()
   Static i As Integer
     'DoEvents
      i = i + 10
      Line2.X2 = i + 1000
      Line2.X1 = i + 1000
      Pause 0.01
      Show
      If i = 5000 Then
         Timer1.Enabled = False
      End If
End Sub