Question

我想创建简单的文本动画。当我单击一个按钮时，文本从完全透明变为完全可见并恢复为透明。我编写了执行动画的代码，但只有一次。每次单击按钮时动画都不再起作用：

function animation() {
  $("span").removeClass("opacity-effect");
  $("span").addClass("opacity-effect");
}

span{
  opacity: 0;
}

.opacity-effect {
  animation-name: animate-opacity-effect;
  animation-duration: 1400ms;
  animation-fill-mode: forwards;
  opacity: 0;

}

@keyframes animate-opacity-effect {
  0% {
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<span>Hello World!</span>
<button onClick="animation()">
   Start animation
</button>

Answer 1

您需要重置动画。使用事件 animationend 有一种很好且正确的方法可以做到这一点。在这种情况下，您需要删除类 opacity-effect。

function animation() {
    $("span").addClass("opacity-effect");
    $("span").on("animationend", function() {
        $(this).removeClass("opacity-effect");
    });
}

span {
    opacity: 0;
}

.opacity-effect {
    animation-name: animate-opacity-effect;
    animation-duration: 1400ms;
    animation-fill-mode: forwards;
    opacity: 0;
}

@keyframes animate-opacity-effect {
    0% {
        opacity: 0;
    }
    50% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<span>Hello World!</span>
<button onClick="animation()">
    Start animation
</button>

Answer 2

动画不重复，因为在没有类的情况下，动画开始CSS需要一个框架。

所以，要解决这个问题，您应该延迟将类添加到下一帧

function animation() {
  $("span").removeClass("opacity-effect");
  requestAnimationFrame(()=>{
    $("span").addClass("opacity-effect");
  });
}

Answer 3

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Dropdown value from database</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  <style>
    span{
        opacity: 0;
    }

    .opacity-effect {
        opacity: 0;
        -webkit-animation: animate-opacity-effect 1400ms infinite;
        -moz-animation: animate-opacity-effect 1400ms infinite;
        -o-animation: animate-opacity-effect 1400ms infinite;
            animation: animate-opacity-effect 1400ms infinite;
    }

    @keyframes animate-opacity-effect  {
        0%   { opacity:1; }
        50%  { opacity:0; }
        100% { opacity:1; }
    }
    @-o-keyframes animate-opacity-effect {
        0%   { opacity:1; }
        50%  { opacity:0; }
        100% { opacity:1; }
    }
    @-moz-keyframes animate-opacity-effect {
        0%   { opacity:1; }
        50%  { opacity:0; }
        100% { opacity:1; }
    }
    @-webkit-keyframes animate-opacity-effect {
        0%   { opacity:1; }
        50%  { opacity:0; }
        100% { opacity:1; }
    }


  </style>
</head>
<body>
    <span>Hello World!</span>
    <button onClick="animation()">
       Start animation
    </button>

<script>
function animation() {
  $("span").removeClass("opacity-effect");
  $("span").addClass("opacity-effect");
}
</script>

</body>
</html>

Answer 4

您需要在 removeClass 和 addClass 之间添加一个小的延迟。这可以通过两种方式完成：

使用 setTimeout

function animation() {
  $("span").removeClass("opacity-effect")
  setTimeout(() => {
    $("span").addClass("opacity-effect");
  }, 0);
}

span{
  opacity: 0;
}

.opacity-effect {
  animation-name: animate-opacity-effect;
  animation-duration: 1400ms;
  animation-fill-mode: forwards;
}

@keyframes animate-opacity-effect {
  0% {
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<span>Hello World!</span>
<button onClick="animation()">
   Start animation
</button>

通过克隆

function animation() {
  const newEl = $("span").removeClass("opacity-effect").clone(true);
  $("span").before(newEl);
  $("span:last").remove();
  newEl.addClass("opacity-effect");
}

span{
  opacity: 0;
}

.opacity-effect {
  animation-name: animate-opacity-effect;
  animation-duration: 1400ms;
  animation-fill-mode: forwards;
}

@keyframes animate-opacity-effect {
  0% {
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<span>Hello World!</span>
<button onClick="animation()">
   Start animation
</button>

Answer 5

$('span').addClass('opacity-effect');
setTimeout(function(){
 $('span').removeClass('opacity-effect');
}, 1400);

试试这个 1400 是您的动画持续时间

动画仅适用于第一次单击按钮

5 个答案: