“setInterval”函数是转储在构造函数中分配的属性

Question

您好我正在尝试在jQuery中创建一个对象，一切都运行正常但不知何故我无法传递一些必要的属性超出setInterval函数bc当我测试它总是弹出“未定义”。这是我的草案代码。

提前致谢!!

   function MyFunction(var1){
     this.var = var1;
     this.var2 = 2;
     this.pause = 3000;
     this.slideOn();
    }

    MyFunction.prototype.slideOn = function(){ 

      alert(this.var); //alerts the value

      setInterval(function(){ //doesnt work and it alerts "undefined"

      alert(this.var2),1000,function(){} 

      },this.pause // works again with no hassle

    };

Answer 1

当你使用＆＃34;这个＆＃34;在一些回调函数中，它使用了作用域＃34;这个＆＃34;。所以，尝试设置＆＃34;外部＆＃34;：

function MyFunction(var1){
 this.var = var1;
 this.var2 = 2;
 this.pause = 3000;
 this.slideOn();
}

MyFunction.prototype.slideOn = function(){ 
  var _this = this;
  alert(_this.var); //alerts the value

  setInterval(function(){ //doesnt work and it alerts "undefined"

  alert(_this.var2),1000,function(){}; //100 and function are senseless

  },_this.pause); // works again with no hassle

};