javascript - 切换 CSS 关键帧

Question

我有一个弹出窗口，它在单击按钮时打开，然后在您单击另一个按钮或弹出窗口之外时关闭。我希望弹出窗口在打开时淡入并在关闭时淡出。如何使用 javascript 在两个关键帧之间切换？

我尝试通过使用 javascript 切换类来做到这一点，但这不起作用。

var popup = document.getElementById("popup");
var popup_content = document.getElementById("popup_content");
var add = document.getElementById("add");
var span = document.getElementById("close");
add.onclick = function() {
  popup.style.display = "block";
  popup.className = "opened";
  popup_content = "opened";
}
span.onclick = function() {
  popup.style.display = "none";
  popup.className = "closed";
  popup_content = "closed";
}
window.onclick = function(event) {
  if (event.target == popup) {
    popup.style.display = "none";
    popup.className = "closed";
    popup_content = "closed";
  }
}

#popup {
  display: none;
  position: fixed;
  z-index: 1;
  padding-top: 100px;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.4);
}

#popup_content {
  position: relative;
  margin: auto;
  background-color: white;
  width: 80%;
  max-width: 500px;
  border-radius: 5px;
  padding: 20px;
  text-decoration: none;
  box-shadow: 0 8px 16px 0 rgba(0, 0, 0, 0.5);
}

.closed {
  -webkit-animation-name: animate-in;
  -webkit-animation-duration: 0.6s;
  animation-name: animate-in;
  animation-duration: 0.6s;
}

.opened {
  -webkit-animation-name: animate-out;
  -webkit-animation-duration: 0.6s;
  animation-name: animate-out;
  animation-duration: 0.6s;
}

@-webkit-keyframes animate-in {
  from {
    opacity: 0
  }
  to {
    opacity: 1
  }
}

@keyframes animate-in {
  from {
    opacity: 0
  }
  to {
    opacity: 1
  }
}

@-webkit-keyframes animate-out {
  from {
    opacity: 1
  }
  to {
    opacity: 0
  }
}

@keyframes animate-out {
  from {
    opacity: 1
  }
  to {
    opacity: 0
  }
}

#close {
  float: right;
  cursor: pointer;
  margin: -15px -15px 0 0;
}

<button id="add">Open popup</button>


<div class="closed" id="popup">
  <div class="closed" id="popup_content">
    <i class="fas fa-times-circle" id="close">Close</i> //////content
  </div>
</div>

实现我的目标的最佳方式是什么？

Answer 1

我会使用过渡 - 请参阅 css 和 js 中关于我更改内容的注释:

var popup = document.getElementById("popup");
var add = document.getElementById("add");
var span = document.getElementById("close");
add.onclick = function() {
  popup.className = "opened";                // only need to transition the popup 
}
span.onclick = function() {
  popup.className = "closed";
}
window.onclick = function(event) {
  if (event.target == popup) {
    popup.className = "closed";
  }
}

#popup {
  position: fixed;
  z-index: 1;
  padding-top: 100px;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.4);
  
  /* add the following and remove the display:none */
  transition: opacity 0.6s;
  opacity: 0;                /* start off closed and opacity 0 to hide */
}
#popup.opened {
  opacity: 1;        /* add opacity 1 so it transitions to be shown */
}

#popup.closed {
  /* this stops the popup from overlaying the content when closed */
  pointer-events:none;
}

#popup_content {
  position: relative;
  margin: auto;
  background-color: white;
  width: 80%;
  max-width: 500px;
  border-radius: 5px;
  padding: 20px;
  text-decoration: none;
  box-shadow: 0 8px 16px 0 rgba(0, 0, 0, 0.5);
}


#close {
  float: right;
  cursor: pointer;
  margin: -15px -15px 0 0;
}

<button id="add">Open popup</button>


<div class="closed" id="popup">
  <div id="popup_content">
    <i class="fas fa-times-circle" id="close">Close</i> //////content
  </div>
</div>