iOS Question how it works ProgressView in B4i

[gudino jose luis]

hiI could not run Progressview in B4i

This is my code:

Sub BarraProgress1(Progress As Long, Total As Long)
ProgressView1.Initialize()
ProgressView1.Progress = Progress/Total

End Sub

note: Progress=50
Total= 100

 

[Erel]

1. Add your views with the designer.
2. Don't initialize the views. They are already initialized.

 

[gudino jose luis]

hi,
Thank you for your prompt response.

This is new code.
but the bar is still not updating

1) Add your views with the designer

BarraProgress1(50,100)

Sub BarraProgress1(Progress As Long, Total As Long)

ProgressView1.Progress = Progress/Total

End Sub

 

[Erel]

Can you upload the project (File - Export as zip)?

 

[Erel]

An example of using ProgressView is attached.

 

[gudino jose luis]

Thank

 

[PierPaduan]

Hi,
I've tested the example, but the progressview doesn't show the progress if it's updated in a For Next cycle. See attached code. It updates only at the end of the cycle.

For i = 0 To 1000
   ProgressView1.Progress = ProgressView1.Progress + 1/1000
   Log(ProgressView1.Progress)
Next

Someone can help me? What I'm doing wrong?
Thanks a Lot.

 

[Erel]

The UI can only be updated when the main thread is free to process the internal message queue.

 

[PierPaduan]

Thanks Erel.

So the way is:
- to break the big For Next cycle into some small cyles,
- start everyone using a timer,
- update the progressview at the end of every cycle.

Correct?

 

[Erel]

What are you doing that takes so long?

A timer is not really needed. You can run the first task and when it completes use CallSubDelayed to run the next one.

 

[PierPaduan]

I'm doing a pdf file in the following way.
There are many diameter and thickness. The pdf may have about 600 lines and the creation takes about 20 seconds in release mode.
The Progressview update only at the end of sub Calc.

Sub Calc
   Unit = "a"
   For diameter = 1 to ....
      Cycle2
   Next

   Unit = "b"
   For diameter = 1 to ....
      Cycle2
   Next

   Unit = "c"
   For diameter = 1 to ....
      Cycle2
   Next
End Sub

Sub Cycle2
   For Thickness = 1 to ....
      CalcParameters
   Next
End Sub

Sub CalcParameters
   ' here the parameters are calculated
   ' according diameter and thickness
   ' and written in the pdf file in a new line
   ' of a table.
End Sub

 

[Erel]

I see. Use CallSubDelayed to run the first sub-task and then the next one when it completes. It will allow the UI to be updated.

 

[PierPaduan]

Hi, Thank
Do you mean to do so? :

'Cycle2
CallSubDelayed(Me, Cycle2)

Because this doesn't work, the progressview doesn't update in release nor in debug mode.
But if I put a breakpoint on the line where the progressview is increased, I can see the progressview increasing after every break.

 

[Erel]

Where did you put it?

Note that the sub name should be a string. You can also use CallSubPlus to add a larger delay.

 

[PierPaduan]

Yes. It was a string.
I will test with CallSubPlus.
Thanks a Lot for your help.