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<!-- 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>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
/ 日期 时间 /
.date-info{
width:160px;
height:28px;
line-height:28px;
text-align:center;
position:absolute;
top:230px;
left:120px;
z-index:11;
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:11;
background-color:#555;
padding:0;
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:7;
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
<div class="jb51code">
<pre class="brush:js;">
(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 = (hour30-90) + (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(' + (minute6 - 90) + 'deg)';
second_line.style.transform = 'rotate(' + (second6 - 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
},"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,{
"left" : R - 0.5 * r * 1.73205 - 0.5 * w,{
"left" : R - r - 0.5 * w,"top": R - 0.5 * r * 1.73205 - 0.5 * h
},"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)";
}
}})();
