とにかく真似して勉強（線を描く）

/**
 * Copyright siny ( http://wonderfl.net/user/siny )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/lesk
 */

package {
	
	import flash.display.Sprite;
	import flash.events.MouseEvent;
    
    public class FlashTest extends Sprite {
    	
    		private var mDown:Boolean = false;
    		private var base:Sprite = new Sprite();
    		
        public function FlashTest() {
			
			base.graphics.beginFill(0xcccccc);
			base.graphics.drawRect(10, 10, 400, 400);
			base.graphics.endFill();
			
			base.graphics.lineStyle(1, 0x000000);
			addChild(base);
			
			base.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
			base.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
			base.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
			
        }
        
        private function onMouseDown(event:MouseEvent):void {
        		mDown = true;
        		base.graphics.moveTo(base.mouseX, base.mouseY);
        }
        
        private function onMouseMove(event:MouseEvent):void {
        		if (mDown) {
        			base.graphics.lineTo(base.mouseX, base.mouseY);
        		}
        }
        
        private function onMouseUp(event:MouseEvent):void {
        		mDown = false;
        }
    }
}