Starling textField 触摸事件

Question

我目前正在尝试创建多个可拖放的文本字段。我之前正在关注一个教程，该教程使用四边形作为您将使用的示例：

var target:Quad = event.target as Quad;

针对您悬停的四边形，我尝试将其更改为

var target:TextField = event.target as TextField;

编译时出现“无法访问空对象引用的属性或方法”的错误。我不太确定问题出在哪里，所以如果有人可以为我解决这个问题，那就太好了。

以下是其余相关代码：

public function onAdded():void{
//stuff that initialises bitmap

for(var i:int=0; i<3; i++){

            //create Textfield
            var bmpFont:starling.text.TextField = new starling.text.TextField(100,100, "test", "Arial", 10);

            bmpFont.fontSize = 50;
            if(i==0){
                bmpFont.color = Color.WHITE;

            }
            else if (i==1){
                bmpFont.color = Color.RED;  
            }

            else if (i==2){
                bmpFont.color = Color.BLUE; 
            }

            bmpFont.x = Math.random() * (stage.stageWidth - bmpFont.width);
            bmpFont.y = stage.stageHeight/2;
            //centering pivot point
            bmpFont.pivotX = 50;
            bmpFont.pivotY = 50;

            //centering code
            //bmpFont.x = stage.stageWidth - bmpFont.width >> 1;
            //bmpFont.y = stage.stageHeight - bmpFont.height >> 1;

            useHandCursor = true;                   
            bmpFont.addEventListener(starling.events.TouchEvent.TOUCH, onTouch);
            parent.addChild(bmpFont);

            }

ontouch 功能：

        //function activating on touch
        public function onTouch(event:starling.events.TouchEvent):void{
            var touches:Vector.<Touch> = event.getTouches(stage, TouchPhase.MOVED);
            //var target:Quad = event.target as Quad;

            var target:starling.text.TextField= event.target as starling.text.TextField

            //single finger manipulations
            if(touches.length == 1){
                var delta:Point = touches[0].getMovement(parent);
                target.x += delta.x;
                target.y += delta.y;
            }

Answer 1

试试

    //function activating on touch
    public function onTouch(event:starling.events.TouchEvent):void{
        var target:starling.text.TextField= event.target as starling.text.TextField;
        var touches:Vector.<Touch> = event.getTouches(target, TouchPhase.MOVED);


        //single finger manipulations
        if(touches.length == 1){
            var delta:Point = touches[0].getMovement(target.parent);
            // delta and target should be not null

            target.x += delta.x;
            target.y += delta.y;
        }