javascript - 同一按钮上的开/关事件

Question

我有一个可与 CSS 配合使用的切换按钮，但我需要在它打开和关闭时添加一些逻辑。问题是 jQuery 无法读取 CSS 上的 :after 和 :before，因为它们实际上不是 DOM 的一部分。

--切换--

<div class="onoffswitch">
    <input type="checkbox" name="onoffswitch" class="onoffswitch-checkbox" id="myonoffswitch">
    <label class="onoffswitch-label" for="myonoffswitch">
        <span id="switch-inner" class="onoffswitch-inner"></span>
        <span class="onoffswitch-switch"></span>
    </label>
</div>

--CSS--

.onoffswitch {
    position: relative; width: 78px;
    -webkit-user-select:none; -moz-user-select:none; -ms-user-select: none;
}
.onoffswitch-checkbox {
    display: none;
}
.onoffswitch-label {
    display: block; overflow: hidden; cursor: pointer;
    border: 2px solid #C2C2C2; border-radius: 20px;
}
.onoffswitch-inner {
    display: block; width: 200%; margin-left: -100%;
    transition: margin 0.3s ease-in 0s;
}
.onoffswitch-inner:before, .onoffswitch-inner:after {
    display: block; float: left; width: 50%; height: 28px; padding: 0; line-height: 28px;
    font-size: 14px; color: white; font-family: Trebuchet, Arial, sans-serif; font-weight: bold;
    box-sizing: border-box;
}
.onoffswitch-inner:before {
    content: "ON";
    padding-left: 10px;
    background-color: #5C7FE3; color: #FFFFFF;
}
.onoffswitch-inner:after {
    content: "OFF";
    padding-right: 10px;
    background-color: #EEEEEE; color: #999999;
    text-align: right;
}
.onoffswitch-switch {
    display: block; width: 18px; margin: 5px;
    background: #FFFFFF;
    position: absolute; top: 0; bottom: 0;
    right: 46px;
    border: 2px solid #C2C2C2; border-radius: 20px;
    transition: all 0.3s ease-in 0s; 
}
.onoffswitch-checkbox:checked + .onoffswitch-label .onoffswitch-inner {
    margin-left: 0;
}
.onoffswitch-checkbox:checked + .onoffswitch-label .onoffswitch-switch {
    right: 0px; 
}

我尝试了 onClick 事件，但每次我点击它(逻辑上)它都会触发代码(如果点击多次则多次)，完美的是一个会是真实的并触发代码并且在第二次点击它会做点别的。

我不知道这是否会 super 简单，我的大脑很累，无法正确思考，但任何帮助都会有帮助!!

Answer 1

添加 click 事件处理程序是正确的方法。只需查看复选框的 checked 属性即可了解按钮的状态(开/关)。

document.getElementById("myonoffswitch").addEventListener("click", function(){
   // Test the state of the checkbox and act accordingly
   if(this.checked){
     console.log("ON");
   } else {
     console.log("OFF");
   }
});

.onoffswitch {
    position: relative; width: 78px;
    -webkit-user-select:none; -moz-user-select:none; -ms-user-select: none;
}
.onoffswitch-checkbox {
    display: none;
}
.onoffswitch-label {
    display: block; overflow: hidden; cursor: pointer;
    border: 2px solid #C2C2C2; border-radius: 20px;
}
.onoffswitch-inner {
    display: block; width: 200%; margin-left: -100%;
    transition: margin 0.3s ease-in 0s;
}
.onoffswitch-inner:before, .onoffswitch-inner:after {
    display: block; float: left; width: 50%; height: 28px; padding: 0; line-height: 28px;
    font-size: 14px; color: white; font-family: Trebuchet, Arial, sans-serif; font-weight: bold;
    box-sizing: border-box;
}
.onoffswitch-inner:before {
    content: "ON";
    padding-left: 10px;
    background-color: #5C7FE3; color: #FFFFFF;
}
.onoffswitch-inner:after {
    content: "OFF";
    padding-right: 10px;
    background-color: #EEEEEE; color: #999999;
    text-align: right;
}
.onoffswitch-switch {
    display: block; width: 18px; margin: 5px;
    background: #FFFFFF;
    position: absolute; top: 0; bottom: 0;
    right: 46px;
    border: 2px solid #C2C2C2; border-radius: 20px;
    transition: all 0.3s ease-in 0s; 
}
.onoffswitch-checkbox:checked + .onoffswitch-label .onoffswitch-inner {
    margin-left: 0;
}
.onoffswitch-checkbox:checked + .onoffswitch-label .onoffswitch-switch {
    right: 0px; 
}

<div class="onoffswitch">
    <input type="checkbox" name="onoffswitch" class="onoffswitch-checkbox" id="myonoffswitch">
    <label class="onoffswitch-label" for="myonoffswitch">
        <span id="switch-inner" class="onoffswitch-inner"></span>
        <span class="onoffswitch-switch"></span>
    </label>
</div>