如何使用css过渡将加号变为减号？

Question

我想创建一个切换button,将其形状从加号变为减号.

仅使用CSS, 不使用伪元素.

我想要的效果是让"+"符号中的垂直线收缩到水平线.

我知道这是可能的,但我不确定哪条路是最佳路线.我正在考虑做一些事情,height但我担心line-height浏览器会改变它在元素中的位置.

$('button').on("click", function(){
  $(this).toggleClass('active');
});

button {
color: #ecf0f1;
background:  #e74c3c;
  width: 50px;
  height: 50px;
  border: 0;
  font-size: 1.5em;
  }
button span {
  transition: all .75s ease-in-out;
  }
button.active span {
  /* Code to morph + to - */
  }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<button><span>+</span></button>

Answer 1

最简单的方法是使用+和-元素(使用伪元素最干净),然后将它们转换为"变形":

button {
  color: #ecf0f1;
  background: #e74c3c;
  width: 50px;
  height: 50px;
  border: 0;
  font-size: 1.5em;
  position: relative;
}

button span {
  position: absolute;
  transition: .3s;
  background: white;
  border-radius: 2px;
}

button span:first-of-type {
  top: 25%;
  bottom: 25%;
  width: 10%;
  left: 45%;
}

button span:last-of-type {
  left: 25%;
  right: 25%;
  height: 10%;
  top: 45%;
}

button:hover span:first-of-type, button:hover span:last-of-type {
  transform: rotate(90deg);
}

button:hover span:last-of-type {
  left: 50%;
  right: 50%;
}

<button>
  <span></span><span></span>
</button>

Answer 2

注意:请停止编辑使答案不正确的问题

CSS解决方案

$('button').on("click", function(){
  $(this).toggleClass('active');
});

button {
  color: #ecf0f1;
  background: #e74c3c;
  width: 70px;
  height: 70px;
  position: relative;
  font-size: 50px;
  cursor: pointer;
  border: 0;
  outline: 0;
  padding: 0
}
.plus,
.minus {
  color: #fff;
  padding: 10px;
  width: 70px;
  height: 70px;
  line-height: 50px;
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  text-align: center;
  box-sizing: border-box;
  transition: .5s all ease-out;
}
.plus {
  opacity: 1;
  transform: rotate(0deg);
}
button.active .plus {
  opacity: 0;
  transform: rotate(90deg);
}
.minus {
  opacity: 0;
  transform: rotate(-90deg);
}
button.active .minus {
  opacity: 1;
  transform: rotate(0deg);
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css" rel="stylesheet" />
<button>
  <span class="plus"><i class="fa fa-plus"></i></span>
  <span class="minus"><i class="fa fa-minus"></i></span>
</button>

一个(旧的)CSS解决方案:

使用::before带有content属性的伪元素

$('button').on("click", function() {
  $(this).toggleClass('active');
});

button {
  color: #ecf0f1;
  background: #e74c3c;
  width: 50px;
  height: 50px;
  border: 0;
  font-size: 1.5em;
}
button span {
  transition: all .75s ease-in-out;
  position:relative
}
button span::before {
  content:"+"
}
button.active span::before {
  content:"-"
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<button><span></span></button>

一个(旧的)jquery解决方案:

不需要span,您可以使用text()jquery中的if语句来执行此操作

$('button').on("click", function() {
  $(this).toggleClass('active');
  $(this).text() == "+" ? $(this).text("-") : $(this).text("+");
});

button {
  color: #ecf0f1;
  background: #e74c3c;
  width: 50px;
  height: 50px;
  border: 0;
  font-size: 1.5em;
  transition: all .75s ease-in-out;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<button>+</button>