利用css+原生js制作简单的钟表。效果如下所示
实现该效果，分三大块：html、javascript、css
html部分
html部分比较简单，定义一个clock的div，内部有原点、时分秒针、日期以及时间，至于钟表上的刻度、数字等元素，因为量比较多，采用jvascript生成
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<link rel='stylesheet' href='外部的css文件路径' />
<title>时钟</title>
</head>
<body>
<div class="clock" id="clock">
<!-- 原点 -->
<div class="origin"></div> <!-- 时分秒针 -->
<div class="clock-line hour-line" id="hour-line"></div>
<div class="clock-line minute-line" id="minute-line"></div>
<div class="clock-line second-line" id="second-line"></div> <!-- 日期 -->
<div class="date-info" id="date-info"></div>
<!-- 时间 -->
<div class="time-info" >
<div class="time" id="hour-time"></div>
<div class="time" id="minute-time"></div>
<div class="time" id="second-time"></div>
</div>
</div>
<script type='text/javascript' src='外部的javascript文件路径'></script>
</body>
</html>
css部分
开始代码之前，有一些css的属性需要了解，比如定位(position)，边框圆角(border-radius),变换(transform)等
position属性
position属性规定元素的定位类型，有五个值：absolute、fixed、relative、static、inherit,默认为static，即没有定位，元素按正常文档流显示；这里主要用到的是absolute和relative
absulte值，将元素设置成绝对定位，相对于static定位意外的第一个上级元素进行定位，位置可以通过’left’、’top’、’right’、’bottom’属性进行定位；如果上级元素都是static定位，则相对于body元素的位置进行定位
本例中，设定最外层的div clock为relative，所有下级元素均设定为absolute绝对定位，然后通过设置left、top等属性的值，确定其相对于clock的位置。
border-radius属性
border-radius属性向元素添加圆角边框，可以设置四个圆角的大小，本例中使用该属性将clock元素设置成一个圆
此处写了一个示例：4个div元素，宽高都是100px，border-radius不同时的效果：
transform属性
transform属性向元素应用2D或3D旋转，该属性允许我们对元素进行旋转、缩放、移动、或倾斜。本例中时针、分针、秒针、刻度等均用transform属性设置旋转；另外，transform-origin属性可以设置元素的基点位置
css部分的代码
/* 全局 */
*{
margin:;
padding:;
}
.clock{
width:400px;
height:400px;
border:10px solid #333;
box-shadow: 0px 0px 20px 3px #444 inset;
border-radius:210px;
position:relative;
margin:5px auto;
z-index:;
background-color:#f6f6f6;
}
/* 时钟数字 */
.clock-num{
width:40px;
height:40px;
font-size:22px;
text-align:center;
line-height:40px;
position:absolute;
z-index:;
color:#555;
font-family:fantasy, 'Trebuchet MS';
}
.em_num{
font-size:28px;
}
/* 指针 */
.clock-line{
position:absolute;
z-index:;
}
.hour-line{width:100px;
height:4px;
top:198px;
left:200px;
background-color:#000;
border-radius:2px;
transform-origin:0 50%;
box-shadow:1px -3px 8px 3px #aaa;
}
.minute-line{
width:130px;
height:2px;
top:199px;
left:190px;
background-color:#000;
transform-origin:7.692% 50%;
box-shadow:1px -3px 8px 1px #aaa;
}
.second-line{
width:170px;
height:1px;
top:199.5px;
left:180px;
background-color:#f60;
transform-origin:11.765% 50%;
box-shadow:1px -3px 7px 1px #bbb;
}
/* 原点 */
.origin{
width:20px;
height:20px;
border-radius:10px;
background-color:#000;
position:absolute;
top:190px;
left:190px;
z-index:;
} /* 日期 时间 */
.date-info{
width:160px;
height:28px;
line-height:28px;
text-align:center;
position:absolute;
top:230px;
left:120px;
z-index:;
color:#555;
font-weight:bold;
font-family:'微软雅黑';
}
.time-info{
width:92px;
height:30px;
line-height:30px;
text-align:center;
position:absolute;
top:270px;
left:154px;
z-index:;
background-color:#555;
padding:;
box-shadow:0px 0px 9px 2px #222 inset;
}
.time{
width:30px;
height:30px;
text-align:center;
float:left;
color:#fff;
font-weight:bold;
}
#minute-time{
border-left:1px solid #fff;
border-right:1px solid #fff;
} /* 刻度 */
.clock-scale{
width:195px;
height:2px;
transform-origin:0% 50%;
z-index:;
position:absolute;
top:199px;
left:200px;
}
.scale-show{
width:12px;
height:2px;
background-color:#555;
float:left;
}
.scale-hidden{
width:183px;
height:2px;
float:left;
}
javascript部分
js部分没什么好说的，简单的dom操作，setInterval函数每隔一秒执行一次，修改指针的角度和显示的时间即可。代码如下
(function(){
window.onload=initNumXY(200, 160, 40,40);
var hour_line = document.getElementById("hour-line");
var minute_line = document.getElementById("minute-line");
var second_line = document.getElementById("second-line");
var date_info = document.getElementById("date-info");
var week_day = [
'星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'
];
var hour_time = document.getElementById("hour-time");
var minute_time = document.getElementById("minute-time");
var second_time = document.getElementById("second-time");
function setTime(){
var this_day = new Date();
var hour = (this_day.getHours() >= 12) ?
(this_day.getHours() - 12) : this_day.getHours();
var minute = this_day.getMinutes();
var second = this_day.getSeconds();
var hour_rotate = (hour*30-90) + (Math.floor(minute / 12) * 6);
var year = this_day.getFullYear();
var month = ((this_day.getMonth() + 1) < 10 ) ?
"0"+(this_day.getMonth() + 1) : (this_day.getMonth() + 1);
var date = (this_day.getDate() < 10 ) ?
"0"+this_day.getDate() : this_day.getDate();
var day = this_day.getDay();
hour_line.style.transform = 'rotate(' + hour_rotate + 'deg)';
minute_line.style.transform = 'rotate(' + (minute*6 - 90) + 'deg)';
second_line.style.transform = 'rotate(' + (second*6 - 90)+'deg)';
date_info.innerHTML =
year + "-" + month + "-" + date + " " + week_day[day];
hour_time.innerHTML = (this_day.getHours() < 10) ?
"0" + this_day.getHours() : this_day.getHours();
minute_time.innerHTML = (this_day.getMinutes() < 10) ?
"0" + this_day.getMinutes() : this_day.getMinutes();
second_time.innerHTML = (this_day.getSeconds() < 10) ?
"0" + this_day.getSeconds():this_day.getSeconds();
}
setInterval(setTime, 1000); function initNumXY(R, r, w, h){
var numXY = [
{
"left" : R + 0.5 * r - 0.5 * w,
"top" : R - 0.5 * r * 1.73205 - 0.5 * h
},
{
"left" : R + 0.5 * r * 1.73205 - 0.5 * w,
"top" : R - 0.5 * r - 0.5 * h
},
{
"left" : R + r - 0.5 * w,
"top" : R - 0.5 * h
},
{
"left" : R + 0.5 * r * 1.73205 - 0.5 * w,
"top" : R + 0.5 * r - 0.5 * h
},
{
"left" : R + 0.5 * r - 0.5 * w,
"top" : R + 0.5 * r * 1.732 - 0.5 * h
},
{
"left" : R - 0.5 * w,
"top" : R + r - 0.5 * h
},
{
"left" : R - 0.5 * r - 0.5 * w,
"top" : R + 0.5 * r * 1.732 - 0.5 * h
},
{
"left" : R - 0.5 * r * 1.73205 - 0.5 * w,
"top" : R + 0.5 * r - 0.5 * h
},
{
"left" : R - r - 0.5 * w,
"top" : R - 0.5 * h
},
{
"left" : R - 0.5 * r * 1.73205 - 0.5 * w,
"top" : R - 0.5 * r - 0.5 * h
},
{
"left" : R - 0.5 * r - 0.5 * w,
"top": R - 0.5 * r * 1.73205 - 0.5 * h
},
{
"left" : R - 0.5 * w,
"top" : R - r - 0.5 * h
}
];
var clock = document.getElementById("clock");
for(var i = 1; i <= 12; i++){
if(i%3 == 0) {
clock.innerHTML += "<div class='clock-num em_num'>"+i+"</div>";
} else {
clock.innerHTML += "<div class='clock-num'>" + i + "</div>";
}
}
var clock_num = document.getElementsByClassName("clock-num");
for(var i = 0; i < clock_num.length; i++) {
clock_num[i].style.left = numXY[i].left + 'px';
clock_num[i].style.top = numXY[i].top + 'px';
}
for(var i = 0; i < 60; i++) {
clock.innerHTML += "<div class='clock-scale'> " +
"<div class='scale-hidden'></div>" +
"<div class='scale-show'></div>" +
"</div>";
}
var scale = document.getElementsByClassName("clock-scale");
for(var i = 0; i < scale.length; i++) {
scale[i].style.transform="rotate(" + (i * 6 - 90) + "deg)";
}
}
})();
