如何使用HTML＆amp; amp;创建旋转效果CSS？

Question

我需要在那个方格的悬停上旋转效果，我能得到的是下面的内容。

HTML

<div class="mainSquare">
  <div class="firstInnerSquare">
    <div class="lastInnerSquare">
      Hello
    </div>
  </div>
</div>

CSS

.mainSquare{
  width:160px;
  height:160px;
  background:black;
  margin: 50px auto;
  padding:25px;
}
.firstInnerSquare{
  width:110px;
  height:110px;
  background:red;
  padding:25px;
}
.lastInnerSquare{
  text-align:center;
  width:110px;
  padding: 46px 0px;
  background:white;
}

Fiddle

希望得到帮助。

Answer 1

您可以使用单个元素和两个伪来完成此操作。使2个伪元素大于容器元素，将它们放在容器后面并向它们添加rotate动画。

注意：这只是一个可以帮助您入门的基础示例。我会留下微调部分供你处理。您可以在this MDN page中阅读有关CSS动画属性的更多信息。

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.shape {
  position: relative; /* used to position the pseudos relative to the parent */
  height: 100px;
  width: 100px;
  background: white;
  border: 1px solid;
  margin: 100px; /* required because children are larger than parent */
}
.shape:after,
.shape:before {
  position: absolute;
  content: '';
}
.shape:before {
  height: 125%; /* make one pseudo 25% larger than parent */
  width: 125%;
  top: -12.5%; /* 25/2 to make sure its center is same as the parent's */
  left: -12.5%; /* 25/2 to make sure its center is same as the parent's */
  background: red;
  z-index: -1; /* send it behind the parent */
}
.shape:after {
  height: 150%; /* make this pseudo larger than the parent and the other pseudo */
  width: 150%;
  top: -25%; /* 50/2 to make sure its center is same as the parent's */
  left: -25%; /* 50/2 to make sure its center is same as the parent's */
  background: black;
  z-index: -2; /* send it behind both the parent and other pseudo */
}

/* add animation when hovering on parent */
.shape:hover:before { 
  animation: rotate 3s linear infinite;
}
.shape:hover:after {
  animation: rotate-rev 3s linear infinite;
}
@keyframes rotate {
  to {
    transform: rotate(359deg); /* some browsers don't display spin when it is 360 deg */
  }
}
@keyframes rotate-rev {
  to {
    transform: rotate(-359deg); /* reverse direction rotate */
  }
}

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<div class='shape'></div>

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Answer 2

这是一个原始结构和一个关键帧声明：

所有需要更改的内容 per div ，是动画的持续时间和方向。 “中间”div的时间需要是外/内的50％。

.mainSquare {
  width: 160px;
  height: 160px;
  background: black;
  margin: 50px auto;
  padding: 25px;
  animation: spin 2s infinite linear;
}
.firstInnerSquare {
  width: 110px;
  height: 110px;
  background: red;
  padding: 25px;
  animation: spin 1s infinite linear reverse;
}
.lastInnerSquare {
  text-align: center;
  width: 110px;
  padding: 46px 0px;
  background: white;
  animation: spin 2s infinite linear;
}
@keyframes spin {
  to {
    transform: rotate(1turn);
  }
}

<div class="mainSquare">
  <div class="firstInnerSquare">
    <div class="lastInnerSquare">
      Hello
    </div>
  </div>
</div>