正在尝试使用transitionend event而不是setTimeout

Question

我有这样的代码：

​

$("#disable").click(function () {
     $("body").append("<div id='blackDisable' class='fade'> </div>");
    setTimeout(function () {
        $("#blackDisable").addClass("showBack");
    }, 150);
});

.fade {
    opacity: 0;
    transition: opacity .15s linear;
}
        
.showBack {
    opacity: .5;
}

#blackDisable {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 2222;
    background-color: black;
}

<button id="disable">Click Me</button>
<script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>

​

我不想使用setTimeout来强制转换工作，所以我搜索了一个解决方案，找到了transitionend事件，并用transitionend事件处理程序替换了setTimeout，但它没有触发。

如何删除此setTimeout并使用transitionend事件？

提前感谢并为我的英语道歉！

Answer 1

transitionend与您的问题有任何关系-因为没有注册任何end的转换。

这是一个立即将类分配给新创建的(还不是DOM样式可发现的)元素的问题- without a callback - setTimeout实际上就像一个“DOM就绪的黑客”。

没有setTimeout？有两种方式(甚至更多)：

1. animation (代替transition)

​

$("#disable").click(function() {

  $("body").append("<div id='blackDisable' class='fade'></div>");
  $("#blackDisable").addClass("showBack");
  
});

.fade {
  opacity: 0;
  /* no transition */
}

.showBack {
  /*opacity: .5; not ready, instead let the browser assign/trigger keyframes */
  animation : fadeIn 0.3s linear forwards;
}

#blackDisable {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 2222;
  background-color: black;
}

@keyframes fadeIn {
  to { opacity: 0.5; }
}

<button id="disable">Click Me</button>
<script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>

​

2.在任何事件之前追加

并使用CSS visibility来防止重叠问题。

​

// Append on DOM ready
$("body").append("<div id='blackDisable' class='fade'></div>");

// CALLBACK
$("#disable").click(function() {
  // Since the callback, it's now discoverable,
  // DOM set, CSS styles are set and we can transition! 
  $("#blackDisable").addClass("showBack");

});

.fade {
  opacity: 0;
  visibility: hidden; /* you need this!!!!!! */
  transition: opacity .3s linear;
}

.showBack {
  opacity: .5;
  visibility: visible; /* and this!!!!!! */
}

#blackDisable {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 2222;
  background-color: black;
}

<button id="disable">Click Me</button>
<script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>

​

3.队列

​

$("#disable").click(function() {

  $("body").append("<div id='blackDisable' class='fade'></div>");
  
  // Instead of setTimeout but again mimicking a callback
  $("#blackDisable").delay().queue(function(){
    $(this).addClass("showBack");
  });
  
});

.fade {
  opacity: 0;
  transition: opacity .3s linear;
}

.showBack {
  opacity: .5;
}

#blackDisable {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 2222;
  background-color: black;
}

<button id="disable">Click Me</button>
<script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>

​