封装了个JS对象没报错也无法运行



 function lb_func(img_locate,num,direction,array){
//img_locate是<img>的id,num是图片的起始号,direction是表示轮播向左或右,array是装图片路径的数组
    this.img_locate = img_locate;
    this.num = num;
    this.direction = direction;
    this.array = array;
    this.prototype = {
        constructor : lb_func,
        move: function(){
            console.log("test");
            //如果点右边
            if( this.direction == "right" ){
                this.num++;
                if (this.num == array.length){
                    this.num = 0;
                }
                findEle(this.img_locate).setAttribute("src",this.array[this.num]);
            }
//findEle()是document.getElementById()
            //如果点左边
            if( this.direction == "left" ){
                this.num--;
                if (this.num < 0 ){
                    this.num = array.length-1;
                }
                findEle(this.img_locate).setAttribute("src",this.array[this.num]);
            }
        }
    }
}

findEle("lb1-right").onclick = new lb_func("lb1-1",a,"right",pics).move;

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肉肉的娇妹妹 9 years, 4 months ago

2个问题
1. prototype属于构造函数的属性,不是实例的属性,构造函数内的this将来是属于实例的,所以不能使用this.prototype。你应该用 arguments.callee.prototype lb_func.prototype 代替。
2. onclick 的执行环境是 HtmlElement 实例,而 move 方法的执行环境是 lb_func 实例,所以你的最后一行的执行环境有问题。你应该改为


 javascript


 findEle("lb1-right").onclick = function () { //该函数的执行环境是find('lb1-right')
    new lb_func("lb1-1",a,"right",pics).move();
}

博丽魔理沙 answered 9 years, 4 months ago

prototype不能放到函数里面去写


 function lb_func(img_locate, num, direction, array) {
    //img_locate是<img>的id,num是图片的起始号,direction是表示轮播向左或右,array是装图片路径的数组
    this.img_locate = img_locate;
    this.num = num;
    this.direction = direction;
    this.array = array;
}


lb_func.prototype.move = function () {
    console.log("test");
    //如果点右边
    if (this.direction == "right") {
        this.num++;
        if (this.num == array.length) {
            this.num = 0;
        }
        findEle(this.img_locate).setAttribute("src", this.array[this.num]);
    }
    //findEle()是document.getElementById()
    //如果点左边
    if (this.direction == "left") {
        this.num--;
        if (this.num < 0) {
            this.num = array.length - 1;
        }
        findEle(this.img_locate).setAttribute("src", this.array[this.num]);
    }
}

轻飘飘的爱恋 answered 9 years, 4 months ago

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