如何使用javascript函数构造函数在每个框上添加点击提醒?

时间:2018-07-31 11:41:15

标签: javascript javascript-events javascript-objects function-constructor

HTML代码:

    <div class="box green">I'm green!</div>
    <div class="box blue">I'm blue!</div>
    <div class="box orange">I'm orange!</div>

此处的CSS代码:

    .green { background-color: green; }
    .blue { background-color: dodgerblue; }
    .orange { background-color: orangered; }

此处的JavaScript代码使用对象文字语法: //要对box2和box3施加相同的效果

var box1 = {
color: 'Green',
number: 1,
clickMe: function () {
    var green = document.querySelector('.green');
    var self = this;

    green.addEventListener('click', function () {

        var str = 'This is box number ' + self.number + ' and it is ' + self.color;

        alert(str);

    });

  }
}

box1.clickMe();

3 个答案:

答案 0 :(得分:1)

如果您希望使用构造函数,则可以使用//Load background texture new THREE.TextureLoader(); loader.load('https://images.pexels.com/photos/1205301/pexels-photo-1205301.jpeg' , function(texture) { scene.background = texture; }); 。您可以使用这样的构造函数(请参见代码段),在该构造函数中接受classcolor

然后,您需要将number中的函数修改为箭头函数(addEventListener),以便在调用时引用正确的() => {}

最后,在创建框时,您需要提供构造函数(this)定义的colornumber

var myBox = new Box(COLOR, NUMBER)
class Box {
  constructor(color, number) {
    this.color = color;
    this.number = number;
  }

  clickMe() {
    var elem = document.querySelector('.' + this.color);
    elem.addEventListener('click', () => {
      var str = 'This is box number ' + this.number + ' and it is ' + this.color;
      alert(str);
    });
  }
}


var box1 = new Box('green', 1);
var box2 = new Box('blue', 2);
var box3 = new Box('orange', 3);

box1.clickMe();
box2.clickMe();
box3.clickMe();
.green { background-color: green; }
.blue { background-color: dodgerblue; }
.orange { background-color: orangered; }

答案 1 :(得分:0)

您可以在clickMe函数中传递参数,并在警报框中使用该参数:

var box1 = {
clickMe: function (color, number) {
    var box = document.querySelector('.'+color);

    box.addEventListener('click', function () {

        var str = 'This is box number ' + number + ' and it is ' + color;

        alert(str);

    });

  }
}

box1.clickMe('green', 1);
box1.clickMe('blue', 2);
box1.clickMe('orange', 3);
.green { background-color: green; }
.blue { background-color: dodgerblue; }
.orange { background-color: orangered; }
<div class="box green">I'm green!</div>
<div class="box blue">I'm blue!</div>
<div class="box orange">I'm orange!</div>

答案 2 :(得分:0)

您可以使用for遍历元素(并一次添加事件侦听器),并使用arrow functionsthis)访问()=>{},如下所示:

var box = {
  color: ['Green', 'Blue', 'Orange'],
  number: [1, 2, 3],
  clickMe: function() {
    var colors = document.getElementsByClassName('box');

    for (let i = 0; i < colors.length; i++) {

      colors[i].addEventListener('click', () => {

        var str = 'This is box number ' + this.number[i] + ' and it is ' + this.color[i];

        alert(str);

      });
    }
  }

这里有一个完整的示例https://jsfiddle.net/25uLvstp/

通过这种方式,您可以一次定义所有box监听器。