如何在多个类(2个以上)之间切换？

Question

我会试着解释我想做什么。如果多个类超过2个，如何在多个类之间切换？当我点击彩色按钮时，容器颜色类将被添加/交换。当我单击白色按钮时，它将删除容器颜色类。

为了更好地理解，这里有一个JSFiddle示例：https://jsfiddle.net/bwd86h4e/1/

我希望有人能帮上忙。谢谢。

HTML：

<div class="buttons">
  <div class="btn btn-reset"></div>
  <div class="btn btn-red"></div>
  <div class="btn btn-green"></div>
  <div class="btn btn-yellow"></div>
</div>

<div class="container">
  When I click on the colored buttons above, then container color class will exchanged. When I click on the white button, then it removes container color class. How to do it?
</div>

CSS：

/* Buttons */
.btn {
  display: inline-block;
  width: 30px;
  height: 30px;
  margin: 3px;
  cursor: pointer;
  border: 2px solid #333;
}
.btn.btn-red { background-color: red; }
.btn.btn-green { background-color: green; }
.btn.btn-yellow { background-color: yellow; }

/* Container */
.container {
  max-width: 480px;
  margin-top: 20px;
  padding: 40px;
  border: 2px solid #333;
}

/* Container color classes */
.container.cont-red { background-color: red; }
.container.cont-green { background-color: green; }
.container.cont-yellow { background-color: yellow; }

Answer 1

像这样的纯javascript：

​

var buttons = document.querySelectorAll(".btn");
var container = document.getElementById("container_1");
var container_color_classes = ["cont-red","cont-green","cont-yellow"];

buttons.forEach(function(button){
		button.addEventListener("click", function(){
  	container_color_classes.forEach(function(color){
    	container.classList.remove(color);
    })
    var className = this.getAttribute("data-class");
    if(className !== null)
    	container.classList.add(className);
  });
});

/* Buttons */
.btn {
  display: inline-block;
  width: 30px;
  height: 30px;
  margin: 3px;
  cursor: pointer;
  border: 2px solid #333;
}
.btn.btn-red { background-color: red; }
.btn.btn-green { background-color: green; }
.btn.btn-yellow { background-color: yellow; }

/* Container */
.container {
  max-width: 480px;
  margin-top: 20px;
  padding: 40px;
  border: 2px solid #333;
}

/* Container color classes */
.container.cont-red { background-color: red; }
.container.cont-green { background-color: green; }
.container.cont-yellow { background-color: yellow; }

<div class="buttons">
  <div class="btn btn-reset"></div>
  <div class="btn btn-red" data-class="cont-red"></div>
  <div class="btn btn-green" data-class="cont-green"></div>
  <div class="btn btn-yellow" data-class="cont-yellow"></div>
</div>

<div class="container" id="container_1">
  When I click on the colored buttons, then container color class will added/exchanged. When I click on the white button, then it removes container color class. <strong>How to do it?</strong>
</div>

​

Answer 2

您可以使用jQuery：

$('.btn').click(function()
{
    var color = $(this).attr('data-class');
    //check to see if el has class btn-reset
    if ($(this).hasClass('btn-reset')) {
        $('.container').attr('class', 'container')
    } else {
        $('.container').attr('class', 'container cont-'+ class)
    }
})

您的html将更改为：

<div class="buttons">
  <div class="btn btn-reset" data-class="reset"></div>
  <div class="btn btn-red" data-class="red"></div>
  <div class="btn btn-green" data-class="green"></div>
  <div class="btn btn-yellow" data-class="yellow"></div>
</div>

参考文献：

https://api.jquery.com/attr/

https://api.jquery.com/addClass/

https://api.jquery.com/hasClass/

jsFiddle：https://jsfiddle.net/fkopmjyx/

Answer 3

您可以使用add class来切换类

let container = $('.container');

$('.btn').click(function(){
  container.attr('class', 'container');
  if($(this).hasClass('btn-red')) container.addClass('cont-red');
  else if($(this).hasClass('btn-green')) container.addClass('cont-green');
  else if($(this).hasClass('btn-yellow')) container.addClass('cont-yellow');
});

https://jsfiddle.net/RACCH/0uwzgf9x/