页面加载完之前显示Loading

1.第一种方式

HTML

<body  class="is-loading">
<div class="curtain">
    <div class="loader">
        loading...
    </div>
</div> 
 <div>
   <!--这里 正文 -->
</div>  
</body>

CSS

.loader {
    position: fixed;
    left: 50%;
    top: 50%;
    margin: -0.2em 0 0 -0.2em;
    text-indent: -9999em;
    border-top: 0.3em solid rgba(0, 0, 0, 0.1);
    border-right: 0.3em solid rgba(0, 0, 0, 0.1);
    border-bottom: 0.3em solid rgba(0, 0, 0, 0.1);
    border-left: 0.3em solid #555;
    -moz-transform: translateZ(0);
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
    -moz-animation: loader 300ms infinite linear;
    -webkit-animation: loader 300ms infinite linear;
    animation: loader 300ms infinite linear;
    -moz-transition: all 500ms ease;
    -o-transition: all 500ms ease;
    -webkit-transition: all 500ms ease;
    transition: all 500ms ease;
}

.loader,
.loader:after {
    border-radius: 50%;
    width: 2em;
    height: 2em;
}

.curtain {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-color: white;
    -moz-transition: all 600ms ease;
    -o-transition: all 600ms ease;
    -webkit-transition: all 600ms ease;
    transition: all 600ms ease;
    filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=0);
    opacity: 0;
    z-index: 0;
    overflow: hidden;
}

@-webkit-keyframes loader {
    0% {
        -webkit-transform: rotate(0deg);
        transform: rotate(0deg);
    }
    100% {
        -webkit-transform: rotate(360deg);
        transform: rotate(360deg);
    }
}

@-moz-keyframes loader {
    0% {
        -moz-transform: rotate(0deg);
        transform: rotate(0deg);
    }
    100% {
        -moz-transform: rotate(360deg);
        transform: rotate(360deg);
    }
}

@keyframes loader {
    0% {
        -webkit-transform: rotate(0deg);
        transform: rotate(0deg);
    }
    100% {
        -webkit-transform: rotate(360deg);
        transform: rotate(360deg);
    }
}

.is-loading {
    overflow: hidden;
}

.is-loading .curtain {
    filter: progid:DXImageTransform.Microsoft.Alpha(enabled=false);
    opacity: 1;
    z-index: 99;
}

.is-loading .loader {
    filter: progid:DXImageTransform.Microsoft.Alpha(enabled=false);
    opacity: 1;
}

JS

 window.onload=function(){
  
     $('body').removeClass('is-loading');  
 }

2.第二种方式

HTML

<div id="loading">  
    <i></i>  
</div>

CSS

#loading{  
  width: 100%;  
  height: 100%;  
  background-color: #fff;  
  position: fixed;  
  top:0;  
  left: 0;  
  z-index: 9999;  
}  
 #loading >i{  
    width: 64px;  
    height: 64px;  
    position: absolute;  
    top:0;  
    bottom:0;  
    left:0;  
    right: 0;  
    margin: auto;  
    background: url("/images/loading.gif") no-repeat;  
  }

JS

document.onreadystatechange = function () {  
    if(document.readyState === "complete"){  
        $("#loading").fadeOut();  
    }  
}

Loading图标网站：https://icons8.com/preloaders/

3.第三种方式

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>css3超炫loading加载特效</title>
<style>
.load1 {
  margin: 100px auto;
  width: 50px;
  height: 60px;
  text-align: center;
  font-size: 10px;
}
.load1 > div {
  background-color: #67CF22;
  height: 100%;
  width: 6px;
  display: inline-block;
  -webkit-animation: stretchdelay 1.2s infinite ease-in-out;
  animation: stretchdelay 1.2s infinite ease-in-out;
}
.load1 .rect2 {
  -webkit-animation-delay: -1.1s;
  animation-delay: -1.1s;
}
.load1 .rect3 {
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}
.load1 .rect4 {
  -webkit-animation-delay: -0.9s;
  animation-delay: -0.9s;
}
.load1 .rect5 {
  -webkit-animation-delay: -0.8s;
  animation-delay: -0.8s;
}
@-webkit-keyframes stretchdelay {
  0%, 40%, 100% { -webkit-transform: scaleY(0.4) }
  20% { -webkit-transform: scaleY(1.0) }
}
@keyframes stretchdelay {
  0%, 40%, 100% {
    transform: scaleY(0.4);
    -webkit-transform: scaleY(0.4);
  }  20% {
    transform: scaleY(1.0);
    -webkit-transform: scaleY(1.0);
  }
}
.load2 {
  width: 60px;
  height: 60px;
  background-color: #67CF22;
  margin: 100px auto;
  -webkit-animation: rotateplane 1.2s infinite ease-in-out;
  animation: rotateplane 1.2s infinite ease-in-out;
}
@-webkit-keyframes rotateplane {
  0% { -webkit-transform: perspective(120px) }
  50% { -webkit-transform: perspective(120px) rotateY(180deg) }
  100% { -webkit-transform: perspective(120px) rotateY(180deg)  rotateX(180deg) }
}
@keyframes rotateplane {
  0% {
    transform: perspective(120px) rotateX(0deg) rotateY(0deg);
    -webkit-transform: perspective(120px) rotateX(0deg) rotateY(0deg)
  } 50% {
    transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
    -webkit-transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg)
  } 100% {
    transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
    -webkit-transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
  }
}
.load3 {
  width: 60px;
  height: 60px;
  position: relative;
  margin: 100px auto;
}
.double-bounce1, .double-bounce2 {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background-color: #67CF22;
  opacity: 0.6;
  position: absolute;
  top: 0;
  left: 0;

  -webkit-animation: bounce 2.0s infinite ease-in-out;
  animation: bounce 2.0s infinite ease-in-out;
}
.double-bounce2 {
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}
@-webkit-keyframes bounce {
  0%, 100% { -webkit-transform: scale(0.0) }
  50% { -webkit-transform: scale(1.0) }
}
@keyframes bounce {
  0%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  } 50% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
  }
}
.load4 {
  margin: 100px auto;
  width: 32px;
  height: 32px;
  position: relative;
}
.cube1, .cube2 {
  background-color: #67CF22;
  width: 30px;
  height: 30px;
  position: absolute;
  top: 0;
  left: 0;
  -webkit-animation: cubemove 1.8s infinite ease-in-out;
  animation: cubemove 1.8s infinite ease-in-out;
}
.cube2 {
  -webkit-animation-delay: -0.9s;
  animation-delay: -0.9s;
}
@-webkit-keyframes cubemove {
  25% { -webkit-transform: translateX(42px) rotate(-90deg) scale(0.5) }
  50% { -webkit-transform: translateX(42px) translateY(42px) rotate(-180deg) }
  75% { -webkit-transform: translateX(0px) translateY(42px) rotate(-270deg) scale(0.5) }
  100% { -webkit-transform: rotate(-360deg) }
}
@keyframes cubemove {
  25% {
    transform: translateX(42px) rotate(-90deg) scale(0.5);
    -webkit-transform: translateX(42px) rotate(-90deg) scale(0.5);
  } 50% {
    transform: translateX(42px) translateY(42px) rotate(-179deg);
    -webkit-transform: translateX(42px) translateY(42px) rotate(-179deg);
  } 50.1% {
    transform: translateX(42px) translateY(42px) rotate(-180deg);
    -webkit-transform: translateX(42px) translateY(42px) rotate(-180deg);
  } 75% {
    transform: translateX(0px) translateY(42px) rotate(-270deg) scale(0.5);
    -webkit-transform: translateX(0px) translateY(42px) rotate(-270deg) scale(0.5);
  } 100% {
    transform: rotate(-360deg);
    -webkit-transform: rotate(-360deg);
  }
}
.load5 {
  margin: 100px auto;
  width: 90px;
  height: 90px;
  position: relative;
  text-align: center;
  -webkit-animation: rotate 2.0s infinite linear;
  animation: rotate 2.0s infinite linear;
}
.dot1, .dot2 {
  width: 60%;
  height: 60%;
  display: inline-block;
  position: absolute;
  top: 0;
  background-color: #67CF22;
  border-radius: 100%;
  -webkit-animation: bounce 2.0s infinite ease-in-out;
  animation: bounce 2.0s infinite ease-in-out;
}
.dot2 {
  top: auto;
  bottom: 0px;
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}
@-webkit-keyframes rotate { 100% { -webkit-transform: rotate(360deg) }}
@keyframes rotate { 100% { transform: rotate(360deg); -webkit-transform: rotate(360deg) }}
@-webkit-keyframes bounce {
  0%, 100% { -webkit-transform: scale(0.0) }
  50% { -webkit-transform: scale(1.0) }
}
@keyframes bounce {
  0%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  } 50% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
  }
}
.load6 {
  margin: 100px auto 0;
  width: 150px;
  text-align: center;
}
.load6 > div {
  width: 30px;
  height: 30px;
  background-color: #67CF22;
  border-radius: 100%;
  display: inline-block;
  -webkit-animation: bouncedelay 1.4s infinite ease-in-out;
  animation: bouncedelay 1.4s infinite ease-in-out;
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
}
.load6 .bounce1 {
  -webkit-animation-delay: -0.32s;
  animation-delay: -0.32s;
}
.load6 .bounce2 {
  -webkit-animation-delay: -0.16s;
  animation-delay: -0.16s;
}
@-webkit-keyframes bouncedelay {
  0%, 80%, 100% { -webkit-transform: scale(0.0) }
  40% { -webkit-transform: scale(1.0) }
}
@keyframes bouncedelay {
  0%, 80%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  } 40% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
  }
}
.load7 {
  width: 40px;
  height: 40px;
  margin: 100px auto;
  background-color: #333;
  border-radius: 100%;
  -webkit-animation: scaleout 1.0s infinite ease-in-out;
  animation: scaleout 1.0s infinite ease-in-out;
}
@-webkit-keyframes scaleout {
  0% { -webkit-transform: scale(0.0) }
  100% {
    -webkit-transform: scale(1.0);
    opacity: 0;
  }
}
@keyframes scaleout {
  0% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  } 100% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
    opacity: 0;
  }
}
.load8 {
  margin: 100px auto;
  width: 20px;
  height: 20px;
  position: relative;
}
.container1 > div, .container2 > div, .container3 > div {
  width: 6px;
  height: 6px;
  background-color: #333;
  border-radius: 100%;
  position: absolute;
  -webkit-animation: bouncedelay 1.2s infinite ease-in-out;
  animation: bouncedelay 1.2s infinite ease-in-out;
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
}
.load8 .load8-container {
  position: absolute;
  width: 100%;
  height: 100%;
}
.container2 {
  -webkit-transform: rotateZ(45deg);
  transform: rotateZ(45deg);
}
.container3 {
  -webkit-transform: rotateZ(90deg);
  transform: rotateZ(90deg);
}
.circle1 { top: 0; left: 0; }
.circle2 { top: 0; right: 0; }
.circle3 { right: 0; bottom: 0; }
.circle4 { left: 0; bottom: 0; }
.container2 .circle1 {
  -webkit-animation-delay: -1.1s;
  animation-delay: -1.1s;
}
.container3 .circle1 {
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}
.container1 .circle2 {
  -webkit-animation-delay: -0.9s;
  animation-delay: -0.9s;
}
.container2 .circle2 {
  -webkit-animation-delay: -0.8s;
  animation-delay: -0.8s;
}
.container3 .circle2 {
  -webkit-animation-delay: -0.7s;
  animation-delay: -0.7s;
}
.container1 .circle3 {
  -webkit-animation-delay: -0.6s;
  animation-delay: -0.6s;
}
.container2 .circle3 {
  -webkit-animation-delay: -0.5s;
  animation-delay: -0.5s;
}
.container3 .circle3 {
  -webkit-animation-delay: -0.4s;
  animation-delay: -0.4s;
}
.container1 .circle4 {
  -webkit-animation-delay: -0.3s;
  animation-delay: -0.3s;
}
.container2 .circle4 {
  -webkit-animation-delay: -0.2s;
  animation-delay: -0.2s;
}
.container3 .circle4 {
  -webkit-animation-delay: -0.1s;
  animation-delay: -0.1s;
}
@-webkit-keyframes bouncedelay {
  0%, 80%, 100% { -webkit-transform: scale(0.0) }
  40% { -webkit-transform: scale(1.0) }
}
@keyframes bouncedelay {
  0%, 80%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  } 40% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
  }
}
</style>
</head>
<body>
<div class="load1">
  <div class="rect1"></div>
  <div class="rect2"></div>
  <div class="rect3"></div>
  <div class="rect4"></div>
  <div class="rect5"></div>
</div>
<div class="load2"></div>
<div class="load3">
  <div class="double-bounce1"></div>
  <div class="double-bounce2"></div>
</div>
<div class="load4">
  <div class="cube1"></div>
  <div class="cube2"></div>
</div>
<div class="load5">
  <div class="dot1"></div>
  <div class="dot2"></div>
</div>
<div class="load6">
  <div class="bounce1"></div>
  <div class="bounce2"></div>
  <div class="bounce3"></div>
</div>
<div class="load7"></div>
<div class="load8">
  <div class="load8-container container1">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
  <div class="load8-container container2">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
  <div class="load8-container container3">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
</div>
</body>
</html>

其他待更新！

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原文地址：https://www.cnblogs.com/eer123/p/8793143.html