CSS3组件化之圆波扩散

本篇文章主要介绍用CSS3实现的水波扩散涟漪，圆波扩散，光圈扩散，雷达波向外散发动画。

预期效果应该是这样：

，其实应该比这个更优美，因为设计师提供的gif出现透明度丢失问题，所以建议用css3实现。

一、明确参数

1、半径

30，42，54
2、透明度

100%，50%，20%
3、颜色

#fb7070

二、实现方案

1、border-width + animation

<div parent="box">
<a id="J_dot"></a>
</div>

div[parent="box"] {
position: relative;
margin:50px auto;
width:54px;
height: 54px;
}
#J_dot{
float: left;
width: 54px;
height: 54px;
box-sizing: border-box;
border-style:double;
border-color: #fb7070;
border-radius: 100%;
animation: circleAnimation 1s infinite alternate;
}

@keyframes circleAnimation {
from {
border-width:0;
}
to {
border-width:27px;
}
}

@-webkit-keyframes circleAnimation {
from {
border-width:0;
}
to {
border-width:27px;
}
}

太假了，整个动画一直固定在大圆圈内，内圆圈似乎在来回放大缩小，离期望值太远！

2、box-shadow + background-color +animation

<div parent="box">
<div class="outer-circle">
<div class="inner-circle"></div>
</div>
</div>

div[parent="box"] {
position:relative;
margin:50px auto;
width:54px;
height:54px;
}
.outer-circle {
animation: circleAnimationOut 1.5s cubic-bezier(0.165, 0.84, 0.44, 1);
}
.inner-circle {
animation: circleAnimationIn 1.5s cubic-bezier(0.165, 0.84, 0.44, 1);
}
.outer-circle, .inner-circle {
position: absolute;
z-index: 10;
width: 30px;
height: 30px;
background: transparent;
border-radius: 100%;
animation-iteration-count: infinite;
}

@keyframes circleAnimationOut {
0% {
box-shadow: 0 0 0 0px rgba(251, 112, 112, 0.5);
}
100% {
box-shadow: 0 0 0 24px rgba(251, 112, 112, 0.2);
}
}
@keyframes circleAnimationIn {
0% {
box-shadow: 0 0 0 0px rgba(251, 112, 112, 0.5);
background-color: rgba(251, 112, 112, 1);
}
100% {
box-shadow: 0 0 0 12px rgba(251, 112, 112, 0.5);
background-color: rgba(251, 112, 112, 1);
}
}

中间实心圆貌似没怎么动啊，效果还凑合。

3、box-shadow + transform +animation

<div parent="box">
<div class="dot"></div>
<div class="inner-circle"></div>
<div class="outer-circle"></div>
</div>

@keyframes circleAnimationIn {
0% {
transform: scale(0.3);
-webkit-transform: scale(0.3);
opacity: 0.0;
}
25% {
transform: scale(0.3);
-webkit-transform: scale(0.3);
opacity: 0.1;
}
50% {
transform: scale(0.5);
-webkit-transform: scale(0.5);
opacity: 0.3;
}
75% {
transform: scale(0.8);
-webkit-transform: scale(0.8);
opacity: 0.5;
}
100% {
transform: scale(1);
-webkit-transform: scale(1);
opacity: 0.0;
}
}
@keyframes circleAnimationOut {
0% {
transform: scale(0.3);
-webkit-transform: scale(0.3);
opacity: 0.0;
}
25% {
transform: scale(0.3);
-webkit-transform: scale(0.3);
opacity: 0.1;
}
50% {
transform: scale(0.3);
-webkit-transform: scale(0.3);
opacity: 0.3;
}
75% {
transform: scale(0.5);
-webkit-transform: scale(0.5);
opacity: 0.5;
}
100% {
transform: scale(0.8);
-webkit-transform: scale(0.8);
opacity: 0.0;
}
}
div[parent="box"] {
position: relative;
margin: 50px auto;
width: 54px;
height: 54px;
}

/* 保持大小不变的小圆点 */
.dot {
position: absolute;
left: 50%;
top: 50%;
width: 20px;
height: 20px;
margin-left: -9px;
margin-top: -9px;
-webkit-border-radius: 50%;
-moz-border-radius: 50%;
border-radius: 50%;
background-color: #fb7070; /* 实心圆 ，如果没有这个就是一个小圆圈 */
z-index: 2;
}

/* 产生动画（向外扩散变大）的圆圈 第一个圆 */
.inner-circle {
position: absolute;
z-index: 1;
width: 54px;
height: 54px;
-webkit-border-radius: 50%;
-moz-border-radius: 50%;
border-radius: 50%;
border: 1px solid #fb7070;
-webkit-animation: circleAnimationIn 2s ease-out;
-moz-animation: circleAnimationIn 2s ease-out;
animation: circleAnimationIn 2s ease-out;
-webkit-animation-iteration-count: infinite;
-moz-animation-iteration-count: infinite;
animation-iteration-count: infinite;
box-shadow: 1px 1px 30px #fb7070;
}

/* 产生动画（向外扩散变大）的圆圈 第二个圆 */
.outer-circle {
position: absolute;
z-index: 1;
width: 54px;
height: 54px;
-webkit-border-radius: 50%;
-moz-border-radius: 50%;
border-radius: 50%;
border: 1px solid #fb7070;
-webkit-animation: circleAnimationOut 2s ease-out;
-moz-animation: circleAnimationOut 2s ease-out;
animation: circleAnimationOut 2s ease-out;
-webkit-animation-iteration-count: infinite;
-moz-animation-iteration-count: infinite;
animation-iteration-count: infinite;
box-shadow: 1px 1px 30px #fb7070;
}