Blinking screen

[aumandg]

I would like to have the background color of the screen to flash from yellow to red when the screen is loaded. I have searched for a sample .aia with no luck. Any help would be great.

[Don Merchant]

As I am just a novice in AI2 I would use the timer (clock) function set to the delay you want to change from first color to the second color...

Initialize your screen with your first color

Enable timer

When timer fires change screen color to second color

Disable timer

In my demo above the timer is set for 1500 mS (1.5 seconds). The screen initializes with yellow background then after timer fires it changes to red.

[aumandg]

I put those blocks in and the sscreenonly changes color from yellow to red, it does not flash back and forth.

[Taifun]

if you want the colors flashing, you have to 

1. remove the Clock.TimerEnabled = false block 

2. change the colors in the Clock.Timer event like this

if Screen.Backgroundcolor = yellow

then set Screen.Backgroundcolor to red

else set Screen.Backgroundcolor to yellow

first do the tutorials http://appinventor.mit.edu/explore/ai2/tutorials.html to learn the basics of App Inventor, then try something and follow the

 Top 5 Tips: How to learn  App Inventor

Taifun

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Trying to push the limits of App Inventor! Snippets and Tutorials from Pura Vida Apps by Taifun.         

[Don Merchant]

Ooops... sorry. Didn't know you wanted it to flash back and forth. You'll need to build a repeat loop with the timer block and add some logic to change to red color if it's yellow and vice versa.

[Don Merchant]

I added a second timer and set both timers to fire but not enabled and set both intervals to 1500.

 

Then I made a couple simple blocks that toggle the timers back and forth, on and off and change the screen colors at the same time. I'm sure there's a better way of doing this.

There's also some additional blocks in there as I was playing with the Day Of Week. But the screen flashes back and forth every 1.5 seconds. 

[Don Merchant]

I knew there would be a simpler way... yes that works too.

[aumandg]

Don, perfect thank you!