Keep "Opening" method code running with While True loop

General
1

I’m creating an onscreen digital clock which I want to refresh every 1 second. I’me using the Datetime method to get the current time (& date) and putting the result in a Label.

This works ok and displays the time when I run the code. But I can’t get the code to refresh.

Coming most recently from Python, I think a While True … Wend loop would do this, but I can’t get it to work. I’ve tried this loop in the Opening method of the time display label, but it never displays the clock and hangs.

Current code:

  'While True
  
  Var d As DateTime = DateTime.Now
  Var Hrint as integer = d.Hour
  Var minint As integer = d.minute
  Var secint As integer = d.second
  Var Hr as String
  Var min as String
  Var sec as String
  
  if Hrint < 10 then  
    Hr = "0" + str(Hrint)
  Else
    Hr = str(Hrint)
  end if
  
  if minint < 10 then  
    min = "0" + str(minint)
  Else
    min = str(minint)
  end if
  
  if secint < 10 then  
    sec = "0" + str(secint)
  Else
    sec = str(secint)
  end if
   
  TimeDisplay.Text = str(Hr) + ":" + str(Min) + ":" + str(sec) 
  
  ' Wend

Sorry - I can’t find how to format the code!

Can anyone please help & point me in the right direction?

2

Use a Timer instead of the loop.

5 Likes
3

Unfortunately, that’s the worst way to do it in Xojo. The While loop blocks the UI update. Use a Timer like Greg suggested.

4

API 1 old Examble clock
https://www.dropbox.com/s/gsuoyxtrfh23tb5/datetimepicker-clock.xojo_binary_project?dl=1

5

Draw your own clock
https://www.dropbox.com/s/uc0robsocgge8yu/Uhr-zeichnen-canvas.xojo_binary_project?dl=1

6

Thank you all for these replies - most helpful, and I think I will be able to proceed now.

Tim - I knew that the while loop I had was blocking the rest of the code - what I didn’t know was what to do about it! But the replies have put me on the right course

Happy Christmas to all

7

str have optional format argument, you could remove this if then and variables too.

https://documentation.xojo.com/api/text/str.html#str
https://documentation.xojo.com/api/text/format.html

8

Thanks MarcusR for that tip - very useful. I didn’t know that format argument was available, but hadn’t really looked - at this stage I’ve just been trying to get the code to work and the other replies have helped with that.

1 Like