请问一下,这是什么问题,为什么按钮不起作用

cc.Class({
extends: cc.Component,

properties: {
    // foo: {
    //    default: null,      // The default value will be used only when the component attaching
    //                           to a node for the first time
    //    url: cc.Texture2D,  // optional, default is typeof default
    //    serializable: true, // optional, default is true
    //    visible: true,      // optional, default is true
    //    displayName: 'Foo', // optional
    //    readonly: false,    // optional, default is false
    // },
    // ...
    paopao_node: cc.Node,
    answerPrefab: cc.Prefab,
},

// use this for initialization
onLoad: function () {
    this.createOption();
},


createOption: function () {
    //console.log("interactiveJson: "+interactiveJson[0].options.length);
    var optionsLength = 5;
    //var answerArr = interactiveJson[0].options;
    //console.log("answerArr[i].optioncontent: "+answerArr[0].optioncontent);
    var stageWidth = this.node.width;
    var bWidth = 244;
    var bHeight = 238;
    var dd = 100;
    var dx = (stageWidth - (optionsLength - 1)*dd - optionsLength*bWidth)/2 + bWidth/2;
    console.log("someloc: "+stageWidth+" "+optionsLength+" "+dx);
    for(var i=0; i<optionsLength; i++)
    {
        
        var btn = cc.instantiate(this.answerPrefab);
        btn = node.getComponent(cc.Button);
        btn.x = dx + i*dd + i*bWidth;
        btn.y = bHeight;
        btn.name = "btn"+i.toString();
        var answerLabel = btn.getChildByName("answerLabel");
        answerLabel.getComponent(cc.Label).string = i.toString();
        //btn = this.node.getComponent(cc.Button);
        //btn.node.clickEvents.push(this.clickEventHandler);
        
        this.paopao_node.addChild(btn);
        
        btn.on('click', this.clickBtn, this);
        //this.btnPool.put(btn);
    }
},

clickBtn: function (event)
{
    console.log("iiiiii");
    console.log(event.detail);
},
// called every frame, uncomment this function to activate update callback
// update: function (dt) {

// },

});

btn.on() 你这个错了,on是node的方法,cc.button没有这个方法