Question

我真的缺乏css动画。我尝试在像谷歌形式的div上创建动画效果。

如果以上链接不起作用（就像我现在的电脑一样），你可以在这里看到它https://ibb.co/cYsYKb

我尝试transition: all 1s ease; background: linear-gradient(to right, #673ab7);但不行。

我试图在谷歌中找到它，但仍然无法解决我的问题，因为我不知道找到它的关键字。

怎么做？欢迎任何建议。

Answer 1

您可以使用 CSS3动画执行此操作：

$(function(){
  $('body').on('focus', 'textarea', function(){
    $(this).next().addClass('active');
  });

  $('body').on('focusout', 'textarea', function(){
    $(this).next().removeClass('active');
  });
});

body {
  background: #fff; 
}
.container {
  position: relative; /* needs to be set since the child has position absolute */
}
textarea {
  width: 100%;
  border: 0;
  outline: 0;
}
.txt-underline {
  background: rgba(0,0,0,0.12);
  height: 1px;
  /* to grow from center: */
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}
.txt-underline.active {
  background: #673ab7;
  height: 2px;
  animation-name: underline; /* "calling" the animation */
  animation-duration: .3s; /* adjust to your needs */
  animation-timing-function: ease; /* also experiment with other values */
  animation-fill-mode: forwards; /* retains 100% width when it gets there */
}
@keyframes underline { /* lets call it the "underline" */
  0%   {width:0} /* start width */
  100% {width:100%} /* end width */
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div class="container">
  <textarea>asddas dasdasdas asdas</textarea>
  <div class="txt-underline"></div>
</div>

Answer 2

您可以在父div上使用:before和:after伪元素来创建此类边框，并通过切换活动类来更改其状态。

＆＃13;

$('.element textarea').on('focus blur', function() {
  $(this).parent('.element').toggleClass('active')
})

＆＃13;

body {
  background-color: #ffffff;
}

.element {
  display: inline-block;
  position: relative;
}
textarea {
  width: 100%;
  border: 0;
  outline: 0;
}
.element:before,
.element:after {
  content: '';
  bottom: 0;
  position: absolute;
  left: 0;
  width: 100%;
  height: 1px;
  background: rgba(0, 0, 0, 0.12);
}

.element:after {
  background:  #673ab7;
  width: 0;
  left: 50%;
  transform: translateX(-50%);
  transition: all 0.3s ease-in;
}

.element.active:after {
  width: 100%;
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="element">
  <textarea>Text</textarea>
</div>

＆＃13;

Answer 3

这就是你想要的......

＆＃13;

* { box-sizing:border-box; }

/* basic stylings ------------------------------------------ */
body 				 { background:url(https://scotch.io/wp-content/uploads/2014/07/61.jpg); }
.container 		{ 
  font-family:'Roboto';
  width:600px; 
  margin:30px auto 0; 
  display:block; 
  background:#FFF;
  padding:10px 50px 50px;
}
h2 		 { 
  text-align:center; 
  margin-bottom:50px; 
}
h2 small { 
  font-weight:normal; 
  color:#888; 
  display:block; 
}
.footer 	{ text-align:center; }
.footer a  { color:#53B2C8; }

/* form starting stylings ------------------------------- */
.group 			  { 
  position:relative; 
  margin-bottom:45px; 
}
input 				{
  font-size:18px;
  padding:10px 10px 10px 5px;
  display:block;
  width:300px;
  border:none;
  border-bottom:1px solid #757575;
}
input:focus 		{ outline:none; }

/* LABEL ======================================= */
label 				 {
  color:#999; 
  font-size:18px;
  font-weight:normal;
  position:absolute;
  pointer-events:none;
  left:5px;
  top:10px;
  transition:0.2s ease all; 
  -moz-transition:0.2s ease all; 
  -webkit-transition:0.2s ease all;
}

/* active state */
input:focus ~ label, input:valid ~ label 		{
  top:-20px;
  font-size:14px;
  color:#5264AE;
}

/* BOTTOM BARS ================================= */
.bar 	{ position:relative; display:block; width:300px; }
.bar:before, .bar:after 	{
  content:'';
  height:4px; 
  width:0;
  bottom:0px; 
  position:absolute;
  background:#5264AE; 
  transition:0.2s ease all; 
  -moz-transition:0.2s ease all; 
  -webkit-transition:0.2s ease all;
}
.bar:before {
  left:50%;
}
.bar:after {
  right:50%; 
}

/* active state */
input:focus ~ .bar:before, input:focus ~ .bar:after {
  width:50%;
}

/* HIGHLIGHTER ================================== */
.highlight {
  position:absolute;
  height:60%; 
  width:100px; 
  top:25%; 
  left:0;
  pointer-events:none;
  opacity:0.5;
}

/* active state */
input:focus ~ .highlight {
  -webkit-animation:inputHighlighter 0.3s ease;
  -moz-animation:inputHighlighter 0.3s ease;
  animation:inputHighlighter 0.3s ease;
}

/* ANIMATIONS ================ */
@-webkit-keyframes inputHighlighter {
	from { background:#5264AE; }
  to 	{ width:0; background:transparent; }
}
@-moz-keyframes inputHighlighter {
	from { background:#5264AE; }
  to 	{ width:0; background:transparent; }
}
@keyframes inputHighlighter {
	from { background:#5264AE; }
  to 	{ width:0; background:transparent; }
}

＆＃13;

<div class="container">
  
  <h2>Material Design in  CSS3<small>Inputs</small></h2>
  
  <form>
    
    <div class="group">      
      <input type="text" required>
      <span class="highlight"></span>
      <span class="bar"></span>
      <label>Name</label>
    </div>
      
    <div class="group">      
      <input type="text" required>
      <span class="bar"></span>
      <label>Email</label>
    </div>
    
    <div class="group">      
      <input type="text" required>
      <span class="highlight"></span>
      <span class="bar"></span>
      <label>Email</label>
    </div>
    
  </form>
      
 
  
</div>

＆＃13;

快乐编码：）

Answer 4

以下是使用CSS3动画制作的快速解决方案以及容器的伪元素：https://jsfiddle.net/nv92uoo4/

$(document).ready(function() {
  $("div").on("click", function() {
  	$(this).addClass("hover")
  });
});

input {
  position: relative;
  border: 0;
  background-color: transparent;
  border-bottom: 1px solid #a0a0a0;
  padding-bottom: 2px;
  outline: 0;
}
div {
  position: relative;
  display: inline-block;
}
div.hover:after {
  content: '';
  display: block;
  height: 2px;
  width: 0;
  background-color: purple;
  animation-duration: 1s;
  animation-name: hover;
  animation-fill-mode: forwards;
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translate(-50%, 0);
}
@keyframes hover {
  from {
    width: 0;
  }
  to {
    width: 100%;
  }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
  <input type="text" value="My value">
</div>

如何像google表单一样向右和向左设置背景颜色中心的动画？

4 个答案: