Help Creating Simple Counter

[SqueezeOJ]

Hello,

I'm trying to create a very simple counter in PowerApps that looks like this:

Here's how I'd like it to work:

• Current count will be stored in variable named myCount
• txtCount.text is set to myCount
• btnUp.onSelect will increment txtCount with Set(myCount,myCount+1)
• btnDown.onSelect will decrement txtCount with Set(myCount,myCount11)
• btnZero.onSelect will set txtCount to 0 (zero) with Set(myCount,0)
• txtCount should never go below 0 (zero) or above 10.  So, it must stay between 0 to 9

My Problems:

1. Can't figure out how to set myCount to 0 (zero) when the App begins.  I'm using App.onStart = Set(myCount,0), but it doesn't do anything - and UpdateContext gives a warning.
2. How do you test the value of myCount and control it with only the very simple events we have available?  I guess, I don't understand where the program flow and logic control would go for a slightly complex application like this.  Any insight is greatly appreciated.

Thank you for your time!

Jason

[CarlosFigueira · Accepted solution]

You're already doing the right thing in initializing the counter:

Screen1.OnStart: Set(myCount, 0)

But you need to close and reopen the app (i.e., save it to your computer, then open it) to have the OnStart executed.

To test the value, you can use the If function in your buttons:

btnUp.OnSelect: If(myCount < 9, Set(myCount, myCount + 1))
btnDown.OnSelect: If(myCount > 0, Set(myCount, myCount - 1))

Another option is to keep the formula as is, but disable the buttons if they cannot be pressed. The properties would look something like those:

btnUp.OnSelect: Set(myCount, myCount + 1)
btnDown.OnSelect: Set(myCount, myCount - 1)
btnUp.DisplayMode: If(myCount < 9, DisplayMode.Edit, DisplayMode.Disabled)
btnDown.DisplayMode: If(myCount > 0, DisplayMode.Edit, DisplayMode.Disabled)

[SqueezeOJ]

Thanks for the solution, Carlos!

I used the DisplayMode approach.  Here's what it looks like now:

At 9 btnUp is disabled

At 0 btnDown is disabled