haxe中bind

 　var sx:Int = 10;
    var sy:Int = 20;
    private function call(fn:Void->Void):Void{
        fn();
    }
    private function gogo(xx:Int,yy:Int):Void{
        trace("xx:"+xx,"yy:"+yy);
        trace("sx:"+sx,"sy:"+sy);
    }

call(gogo.bind(sx,sy));

Timer.delay(gogo.bind(sx,sy),1000);
//call(gogo.bind(sx,sy));
        sx= sy = 10;

 sp= new FlxSprite();
        _testGroup.add(sp);//一个displayobjectcontainer
        call(gogo.bind(sp));
        Timer.delay(gogo.bind(sp),1000);
        sp.alpha = 0;

   var sp:FlxSprite;
    private function call(fn:Void->Void):Void{
        fn();
    }
    private function gogo(sp:FlxSprite):Void{
        trace("alpha"+sp.alpha);
    }