最近项目里遇到一个有意思的效果,那就是圆形进度条,类似于这样的:
实现类似这样的效果方法很多。我主要想了2个解决方案,都是通过jQuery和CSS实现的,下面就一一道来:
方法一:jQuery + CSS3
实现原理
原理非常的简单,在这个方案中,最主要使用了CSS3的transform中的rotate和CSS3的clip两个属性。用他们来实现半圆和旋转效果。
半环的实现
先来看其结构。
HTML
<div class="pie_right">
<div class="right"></div>
<div class="mask"><span>0</span>%</div>
</div>
结构非常简单。这样的结构,大家一看就清楚。
CSS
.pie_right {
width:200px;
height:200px;
position: absolute;
top: 0;
left: 0;
background:#0cc;
}
.right {
width:200px;
height:200px;
background:#00aacc;
border-radius: 50%;
position: absolute;
top: 0;
left: 0;
}
.pie_right, .right {
clip:rect(0,auto,auto,100px);
}
.mask {
width: 150px;
height: 150px;
border-radius: 50%;
left: 25px;
top: 25px;
background: #FFF;
position: absolute;
text-align: center;
line-height: 150px;
font-size: 20px;
background: #0cc;
/* mask 是不需要剪切的,此处只是为了让大家看到效果*/
clip:rect(0,auto,auto,75px); }
实现半圆还是挺简单的,利用border-radius做出圆角,然后利用clip做出剪切效果,(clip使用方法,详见站内介绍),mask的部分是为了遮挡外面的容器,致使在视觉上产生圆环的效果:
旋转的话,那更容易实现了,就是在CSS的right中加入(我没做浏览器兼容代码,请大家自行加入):
.right {
transform: rotate(30deg);
}
这样就可以看到一个半弧旋转的效果了。
整环的实现
同样道理,拼接左半边圆环,为了让我们html结构更易懂以后写js更简便,我对结构做了一下改造,并作了效果优化:
HTML
<div class="circle">
<div class="pie_left"><div class="left"></div></div>
<div class="pie_right"><div class="right"></div></div>
<div class="mask"><span>0</span>%</div>
</div>
CSS
.circle {
width: 200px;
height: 200px;
position: absolute;
border-radius: 50%;
background: #0cc;
}
.pie_left, .pie_right {
width: 200px;
height: 200px;
position: absolute;
top: 0;left: 0;
}
.left, .right {
display: block;
width:200px;
height:200px;
background:#00aacc;
border-radius: 50%;
position: absolute;
top: 0;
left: 0;
transform: rotate(30deg);
}
.pie_right, .right {
clip:rect(0,auto,auto,100px);
}
.pie_left, .left {
clip:rect(0,100px,auto,0);
}
.mask {
width: 150px;
height: 150px;
border-radius: 50%;
left: 25px;
top: 25px;
background: #FFF;
position: absolute;
text-align: center;
line-height: 150px;
font-size: 16px;
}
效果如下:
圆环最终效果
Ok了,基本上我们的圆环已经实现完成了,下面是加入JS效果。
首先,我们需要考虑的是,圆环的转动幅度大小,是由圆环里面数字的百分比决定的,从0%-100%,那么圆弧被分成了每份3.6°;而在180°,也就是50%进度之前,左侧的半弧是不动的,当超过50%,左边的半弧才会有转动显示。
那么,原理明确之后,其jQuery代码如下(删除CSS中的旋转效果,在JS里重写):
$(function() {
$('.circle').each(function(index, el) {
var num = $(this).find('span').text() * 3.6;
if (num<=180) {
$(this).find('.right').css('transform', "rotate(" + num + "deg)");
} else {
$(this).find('.right').css('transform', "rotate(180deg)");
$(this).find('.left').css('transform', "rotate(" + (num - 180) + "deg)");
};
});
});
则,改变mask里面的span 的数值,我们就会看到最终效果。
这样我们只要从后台获取当前流程的进度值,传给span,那么我们页面上就能看到这样圆环的进度效果啦。
jQuery + 图片
实现原理
这种方法相对来说就比较简单了,但是也是挺麻烦的一种。
首先,我们需要一个非常冗长的一个图片……图片的内容,就是每1°旋转角度,就是一张图片…100张…
例如:
然后让容器为这个图片为背景,理由用background-position写100个类样式做背景偏移…很累啊….进度每改变一下,就引用相对应的类。
HTML
我们类似于有这样的一个结构,当然这里面有很多个这样的结构:
<div class="progressbar">
<span>0</span>%
</div>
比如说我们的案例的中结构:
<div class="progressbar">
<span>10</span>%
</div>
<div class="progressbar">
<span>20</span>%
</div>
<div class="progressbar">
<span>30</span>%
</div>
<div class="progressbar">
<span>50</span>%
</div>
<div class="progressbar">
<span>70</span>%
</div>
<div class="progressbar">
<span>90</span>%
</div>
<div class="progressbar">
<span>100</span>%
</div>
CSS
样式是比较苦逼的事情,我们需要在每个位置修改他的background-position。也就是从0%~100%,将会有100个:
.progressbar {
text-align: center;
line-height: 44px;
width: 44px;
display: block;
background: url(progressbar.png);
height: 44px;
font-size: 14px;
margin-left:60px;
}
.progressbar-1 {background-position: 0px 0px;}
.progressbar-2 {background-position: -54px 0px;}
.progressbar-3 {background-position: -108px 0px;}
.progressbar-4 {background-position: -162px 0px;}
.progressbar-5 {background-position: -216px 0px;}
.progressbar-6 {background-position: -270px 0px;}
.progressbar-7 {background-position: -324px 0px;}
.progressbar-8 {background-position: -378px 0px;}
.progressbar-9 {background-position: -432px 0px;}
.progressbar-10 {background-position: -486px 0px;}
.progressbar-11 {background-position: -540px 0px;}
.progressbar-12 {background-position: -594px 0px;}
.progressbar-13 {background-position: -648px 0px;}
.progressbar-14 {background-position: -702px 0px;}
.progressbar-15 {background-position: -756px 0px;}
.progressbar-16 {background-position: -810px 0px;}
.progressbar-17 {background-position: -864px 0px;}
.progressbar-18 {background-position: -918px 0px;}
.progressbar-19 {background-position: -972px 0px;}
.progressbar-20 {background-position: -1026px 0px;}
.progressbar-21 {background-position: -1080px 0px;}
.progressbar-22 {background-position: -1134px 0px;}
.progressbar-23 {background-position: -1188px 0px;}
.progressbar-24 {background-position: -1242px 0px;}
.progressbar-25 {background-position: -1296px 0px;}
.progressbar-26 {background-position: -1350px 0px;}
.progressbar-27 {background-position: -1404px 0px;}
.progressbar-28 {background-position: -1458px 0px;}
.progressbar-29 {background-position: -1512px 0px;}
.progressbar-30 {background-position: -1566px 0px;}
.progressbar-31 {background-position: -1620px 0px;}
.progressbar-32 {background-position: -1674px 0px;}
.progressbar-33 {background-position: -1728px 0px;}
.progressbar-34 {background-position: -1782px 0px;}
.progressbar-35 {background-position: -1836px 0px;}
.progressbar-36 {background-position: -1890px 0px;}
.progressbar-37 {background-position: -1944px 0px;}
.progressbar-38 {background-position: -1998px 0px;}
.progressbar-39 {background-position: -2052px 0px;}
.progressbar-40 {background-position: -2106px 0px;}
.progressbar-41 {background-position: -2160px 0px;}
.progressbar-42 {background-position: -2214px 0px;}
.progressbar-43 {background-position: -2268px 0px;}
.progressbar-44 {background-position: -2322px 0px;}
.progressbar-45 {background-position: -2376px 0px;}
.progressbar-46 {background-position: -2430px 0px;}
.progressbar-47 {background-position: -2484px 0px;}
.progressbar-48 {background-position: -2538px 0px;}
.progressbar-49 {background-position: -2592px 0px;}
.progressbar-50 {background-position: -2700px 0px;}
.progressbar-51 {background-position: -2754px 0px;}
.progressbar-52 {background-position: -2808px 0px;}
.progressbar-53 {background-position: -2862px 0px;}
.progressbar-54 {background-position: -2916px 0px;}
.progressbar-55 {background-position: -2970px 0px;}
.progressbar-56 {background-position: -3024px 0px;}
.progressbar-57 {background-position: -3078px 0px;}
.progressbar-58 {background-position: -3132px 0px;}
.progressbar-59 {background-position: -3186px 0px;}
.progressbar-60 {background-position: -3240px 0px;}
.progressbar-61 {background-position: -3294px 0px;}
.progressbar-62 {background-position: -3348px 0px;}
.progressbar-63 {background-position: -3402px 0px;}
.progressbar-64 {background-position: -3456px 0px;}
.progressbar-65 {background-position: -3510px 0px;}
.progressbar-66 {background-position: -3564px 0px;}
.progressbar-67 {background-position: -3618px 0px;}
.progressbar-68 {background-position: -3672px 0px;}
.progressbar-69 {background-position: -3726px 0px;}
.progressbar-70 {background-position: -3780px 0px;}
.progressbar-71 {background-position: -3834px 0px;}
.progressbar-72 {background-position: -3888px 0px;}
.progressbar-73 {background-position: -3942px 0px;}
.progressbar-74 {background-position: -3996px 0px;}
.progressbar-75 {background-position: -4050px 0px;}
.progressbar-76 {background-position: -4104px 0px;}
.progressbar-77 {background-position: -4158px 0px;}
.progressbar-78 {background-position: -4212px 0px;}
.progressbar-79 {background-position: -4266px 0px;}
.progressbar-80 {background-position: -4320px 0px;}
.progressbar-81 {background-position: -4376px 0px;}
.progressbar-82 {background-position: -4428px 0px;}
.progressbar-83 {background-position: -4482px 0px;}
.progressbar-84 {background-position: -4536px 0px;}
.progressbar-85 {background-position: -4590px 0px;}
.progressbar-86 {background-position: -4644px 0px;}
.progressbar-87 {background-position: -4698px 0px;}
.progressbar-88 {background-position: -4752px 0px;}
.progressbar-89 {background-position: -4806px 0px;}
.progressbar-90 {background-position: -4860px 0px;}
.progressbar-91 {background-position: -4914px 0px;}
.progressbar-92 {background-position: -4968px 0px;}
.progressbar-93 {background-position: -5022px 0px;}
.progressbar-94 {background-position: -5076px 0px;}
.progressbar-95 {background-position: -5130px 0px;}
.progressbar-96 {background-position: -5184px 0px;}
.progressbar-97 {background-position: -5238px 0px;}
.progressbar-98 {background-position: -5292px 0px;}
.progressbar-99 {background-position: -5346px 0px;}
.progressbar-100 {background-position: -5400px 0px;}
JavaScript
当然,在这个效果中,我们也离不开JavaScript:
$(function() {
$('.progressbar').each(function(index, el) {
var num = $(this).find('span').text();
$(this).addClass('progressbar-' + num);
});
});
效果如下:
虽然这种方法虽然比较繁琐比较麻烦,但是实现出来的效果,也较纯css3的丰富,兼容性也更好。
到这里,这个案例算是完成,看大家倾向于那种效果吧,个人感觉各有利弊各有春秋。如果有更好的方法和思路,欢迎大家一起讨论。