How do I make the action happen every time the button is pressed?
local function onKeyEvent( event ) if ( event.keyName == "up" ) then ballvel = ballvel - 0.1; end if ( event.keyName == "down" ) then ballvel = ballvel + 0.1; end return true end Runtime:addEventListener( "key", onKeyEvent ) function update(event) balloon.y = balloon.y + ballvel; print(ballvel); end Runtime:addEventListener("enterFrame", update)Your title says “while” and body says “every time the button is pressed”, so it’s not 100% clear which you mean.
Simplest approach would be be to just toggle a function’s listener on or off depending on whether a desired key is held down or not and then adjust the direction based on what key was last pressed. Something along these lines:
local value, change = 1000 local function updateValue() value = value + change print( value ) end local function onKeyEvent( event ) if event.keyName == "down" then if event.phase == "down" then change = -1 Runtime:addEventListener( "enterFrame", updateValue ) else Runtime:removeEventListener( "enterFrame", updateValue ) end elseif event.keyName == "up" then if event.phase == "down" then change = 1 Runtime:addEventListener( "enterFrame", updateValue ) else Runtime:removeEventListener( "enterFrame", updateValue ) end end return false end Runtime:addEventListener( "key", onKeyEvent )I have a balloon.
It always moves up or down depending on its ballvel variable.
when a key is pressed, this variable changes.
How do I make the variable change not in steps, but all the time while the key is pressed?
How? By reading my previous answer and adopting it to yours.
lol 
All the same, adding to the variable goes in steps.
I’m not sure what you mean. My code increases or decreases the value as long as a key is held down. Have you even tried running it?