JavaScript CSS动画只能使用一次

Question

我有一个银行应用程序，有一个超级酷的手下来，并将一枚硬币放入存钱罐。问题是，只有一只手掉落硬币然后停止工作。

这是我的代码：

* {
  margin:0px;
  padding:0px;
}

body {
  background-image:url('../images/bg.png');
}

@keyframes moveDown {
  0% {}
  100% {margin-top:-220px;}
}

@keyframes fadeIn {
  0% {opacity:0;}
  90%{opacity:1}
  100%{opacity:0;}
}

#hand {
  height:300px;
  width:300px;
  position:absolute;
  left:50%;
  margin-left:-120px;
  margin-top:-350px;
  background-image:url("../images/hand.png");
  opacity:0;
}

#pigBox {
  margin-left:auto;
  margin-right:auto;
  height:600px;
  width:500px;
  margin-top:250px;
  position:relative;

  img {
    margin:0px 50px;
  }

}

input[type=text] {
  float:left;
  display:block;
  font-size:2em;
  width:500px;
  border-radius:10px;
  border:solid 2px pink;
  margin-top:10px;
  font-family: 'Gochi Hand', cursive;
  text-align:center;
  padding:2px;
}

#deposit {
  float:left;
  display:block;
  font-family: 'Gochi Hand', cursive;
  font-size:2em;
  clear:left;
  width:200px;
  margin:10px 25px;
  border-radius:10px;
  background-color:pink;
  border:solid 2px pink;
  padding:2px;
  cursor:pointer;

  &:hover {
    background-color:white;
  }
}

#withdraw {
  float:left;
  display:block;
  font-family: 'Gochi Hand', cursive;
  font-size:2em;
  width:200px;
  margin:10px 25px;
  border-radius:10px;
  background-color:pink;
  border:solid 2px pink;
  padding:2px;
  cursor:pointer;

  &:hover {
    background-color:white;
  }
}

label {
  text-align:center;
  display:block;
  font-family: 'Gochi Hand', cursive;
  font-size:2.5em;
  border-radius:10px;
  width:300px;
  margin-left:100px;
  margin-right:100px;
  margin-top:5px;
  margin-bottom:-15px;
}

document.getElementById('balance').value = "1000"

var balance = document.getElementById('balance').value;
var deposit = document.getElementById('deposit');
var withdraw = document.getElementById('withdraw');
var hand = document.getElementById('hand');

deposit.addEventListener('click', depositCash);
withdraw.addEventListener('click', withdrawCash);

function depositCash() {
  var depositAmt = prompt('How much would you like to deposit?');

  if(depositAmt != Number(depositAmt)) {
    return alert('Please enter a valid integer.');
  }
  else if (Number(depositAmt) < 0) {
    return alert('Please enter a positive integer.');
  }

  hand.style.animation = 'moveDown 1.5s ease-in-out, fadeIn 1.5s ease-in-out';
  balance = Number(balance) + Number(depositAmt);
  document.getElementById('balance').value = balance;
}

function withdrawCash() {
  var withdrawAmt = prompt('How much you you like to withdraw?');

  if(withdrawAmt != Number(withdrawAmt)) {
    return alert('Please enter a valid integer.');
  }
  else if (Number(withdrawAmt) < 0) {
    return alert('Please enter a positive integer.');
  }
  else if(withdrawAmt > balance) {
    return alert("Your balance isn't large enough to withdraw that amount!")
  }


  balance = Number(balance) - Number(withdrawAmt);
  document.getElementById('balance').value = balance;
}

<section id="pigBox">
      <div id="hand"></div><!-- end of hand-->
      <img src="images/pig.png" />
      <label>Balance: </label><input type="text" id="balance" />
      <button id="deposit"> Deposit </button>
      <button id="withdraw"> Withdraw </button>
  </section><!-- end of pigBox-->

<a href="http://imgur.com/FxwmGFi"><img src="http://i.imgur.com/FxwmGFi.png" title="source: imgur.com" /></a>

当你把钱存入存钱罐时，请注意hand.style动画。

有什么想法吗？

谢谢！

Answer 1

这是因为CSS animations don't automatically restart。特别是因为你没有定义时间循环，所以它只执行一次。

一种方法是使用.addClass（'x'）。removeClass（'x'）重新触发在类X上定义的动画。

.addClass（）当然是jQuery。你可以在vanilla JS中使用相同的方法，例如，hand.className + ='my-animation';并按照以下方法重置在方法的顶部。

//ref: https://css-tricks.com/restart-css-animation/

document.getElementById('balance').value = "1000"

var balance = document.getElementById('balance').value;
var deposit = document.getElementById('deposit');
var withdraw = document.getElementById('withdraw');
var hand = document.getElementById('hand');

deposit.addEventListener('click', depositCash);
withdraw.addEventListener('click', withdrawCash);

function depositCash() {
  hand.className = 'randoImage';
  var depositAmt = prompt('How much would you like to deposit?');

  if(depositAmt != Number(depositAmt)) {
    return alert('Please enter a valid integer.');
  }
  else if (Number(depositAmt) < 0) {
    return alert('Please enter a positive integer.');
  }

  hand.className += ' my-animation';
  balance = Number(balance) + Number(depositAmt);
  document.getElementById('balance').value = balance;
}

function withdrawCash() {
  var withdrawAmt = prompt('How much you you like to withdraw?');

  if(withdrawAmt != Number(withdrawAmt)) {
    return alert('Please enter a valid integer.');
  }
  else if (Number(withdrawAmt) < 0) {
    return alert('Please enter a positive integer.');
  }
  else if(withdrawAmt > balance) {
    return alert("Your balance isn't large enough to withdraw that amount!")
  }


  balance = Number(balance) - Number(withdrawAmt);
  document.getElementById('balance').value = balance;
}

.randoImage {
  width: 25px;
  height: 25px;
  background-image: url(data:image/gif;base64,R0lGODlhEAAQAMQAAORHHOVSKudfOulrSOp3WOyDZu6QdvCchPGolfO0o/XBs/fNwfjZ0frl3/zy7////wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAkAABAALAAAAAAQABAAAAVVICSOZGlCQAosJ6mu7fiyZeKqNKToQGDsM8hBADgUXoGAiqhSvp5QAnQKGIgUhwFUYLCVDFCrKUE1lBavAViFIDlTImbKC5Gm2hB0SlBCBMQiB0UjIQA7);
}

* {
  margin:0px;
  padding:0px;
}

@keyframes moveDown {
  0% {}
  100% {margin-top:-220px;}
}

@keyframes fadeIn {
  0% {opacity:0;}
  90%{opacity:1}
  100%{opacity:0;}
}

#hand {
  height:300px;
  width:300px;
  position:absolute;
  left:50%;
  margin-left:-120px;
  margin-top:-350px;
  /*background-image:url("../images/hand.png");*/
  opacity:0;
}

#pigBox {
  margin-left:auto;
  margin-right:auto;
  height:600px;
  width:500px;
  margin-top:250px;
  position:relative;

  img {
    margin:0px 50px;
  }

}

input[type=text] {
  float:left;
  display:block;
  font-size:2em;
  width:500px;
  border-radius:10px;
  border:solid 2px pink;
  margin-top:10px;
  font-family: 'Gochi Hand', cursive;
  text-align:center;
  padding:2px;
}

#deposit {
  float:left;
  display:block;
  font-family: 'Gochi Hand', cursive;
  font-size:2em;
  clear:left;
  width:200px;
  margin:10px 25px;
  border-radius:10px;
  background-color:pink;
  border:solid 2px pink;
  padding:2px;
  cursor:pointer;

  &:hover {
    background-color:white;
  }
}

#withdraw {
  float:left;
  display:block;
  font-family: 'Gochi Hand', cursive;
  font-size:2em;
  width:200px;
  margin:10px 25px;
  border-radius:10px;
  background-color:pink;
  border:solid 2px pink;
  padding:2px;
  cursor:pointer;

  &:hover {
    background-color:white;
  }
}

label {
  text-align:center;
  display:block;
  font-family: 'Gochi Hand', cursive;
  font-size:2.5em;
  border-radius:10px;
  width:300px;
  margin-left:100px;
  margin-right:100px;
  margin-top:5px;
  margin-bottom:-15px;
}

.my-animation {
  animation: moveDown 1.5s ease-in-out, fadeIn 1.5s ease-in-out;
}

<section id="pigBox">
      <div class="randoImage" id="hand"></div><!-- end of hand-->
      <img class="randoImage" />
      <!--<img src="images/pig.png" />-->
      <label>Balance: </label><input type="text" id="balance" />
      <button id="deposit"> Deposit </button>
      <button id="withdraw"> Withdraw </button>
  </section><!-- end of pigBox-->

Answer 2

您应该在动画后删除Hand的样式（在脚本中添加3行）：

...

var myHand = false;

deposit.addEventListener（＆＃39;点击＆＃39;，depositCash）;

withdraw.addEventListener（＆＃39;点击＆＃39;，withdrawCash）;

function depositCash（）{

if（myHand）clearTimeout（myHand）;

...

hand.style.animation =＆＃39; moveDown 1.5s easy-in-out，fadeIn 1.5s ease-in-out＆＃39;;

balance = Number（balance）+ Number（depositAmt）;

document.getElementById（＆＃39;余额＆＃39;）。value = balance;

myHand = setTimeout（function（）{hand.style.animation =＆＃39;＆＃39;;}，2000）;

}

Answer 3

遇到同样的问题。

对于那些使用jQuery的人，这是我的解决方案。

我意识到，如果我们将 .addClass（）。removeClass（）串在一起，jQuery会解释和否定这两个命令，因此不会发生任何变化。因此，我建议使用超时功能的解决方法：

让 animationTimeout

clearTimeout （animationTimeout）

$（'＃animatedElement'）。 addClass （'animation'）

animationTimeout = setTimeout （（）=> {$（'＃animatedElement'）。 removeClass （'animation'）}，animationDuration）

Answer 4

使用动画svgs的快速简单的解决方案是使用随机查询（例如）加载图片；

假定具有现有功能loadImage的javascript环境

loadImage（'image.svg？u ='+ new Date（）。getMilliseconds（））;

您欺骗浏览器，以为它的文件不一样，动画就开始了。