Question

I usually used as3 in flash to develop game, but I always do for a fixed size of file. But in itunes there are a lot of app work for both ipad – 768×1024 and iphone 640×940 (this size is iphone 4) and even different iphone generation has different size too. So how can i use flash to make one app that can work for all of these devices?

Answer 1

you want to create your application to target multiscreens. doing so involves a few additional steps, but the overall process is quite straight-forward.

generally, the process involves sizing your stage at start up to be the same size as the screen and then sizing and positioning your display objects at runtime according to the size of the stage, or simply the screen size:

package
{
    import flash.display.Screen;
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.geom.Rectangle;    

    [SWF(backgroundColor = "0x555555")]
    public class MultiscreenApplication extends Sprite
    {
        public static var screenBounds:Rectangle = Screen.mainScreen.visibleBounds;

        public function MultiscreenApplication()
        {
            stage.scaleMode = StageScaleMode.NO_SCALE;
            stage.align = StageAlign.TOP_LEFT;
            stage.frameRate = 60;

            init();
        }

        private function init():void
        {

        }
    }
}

there are several well-read online resources at Adobe to guide you thru the steps, including Christian Cantrell’s Writing multiscreen AIR apps and Authoring mobile Flash content for multiple screen sizes. there was also a webinar during last year’s Adobe MAX which you can watch here: Multiscreen Development Techniques with Flex and Adobe AIR