这期内容当中小编将会给大家带来有关怎么在html5中实现一个时钟功能，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。
<!DOCTYPE HTML><html><head> <meta charset="UTF-8"> <style type="text/css"> canvas{position:absolute;top:0px;left:0px;} </style> <title>时钟</title></head><body> <canvas id="canvas" width="200" height="200"></canvas> <canvas id="p_canvas" width="200" height="200"></canvas> <script type="text/javascript"> //获取绘图对象 var canvas = document.getElementById('canvas'); var context = canvas.getContext('2d'); var p_canvas = document.getElementById('p_canvas'); var p_context = p_canvas.getContext('2d'); var height=200,width=200; //画大圆 context.beginPath(); context.strokeStyle="#009999"; context.arc(width/2,height/2,width/2-1,0,Math.PI*2,true); context.stroke(); context.closePath(); //画中间点 context.beginPath(); context.fillStyle="#000"; context.arc(width/2,height/2,3,0,Math.PI*2,true); context.fill(); context.closePath(); //画小刻度 var angle = 0,radius = width/2 - 4; for(var i=0;i<60;i++){ context.beginPath(); context.strokeStyle="#000"; //确认刻度的起始点 var x = width/2 + radius*Math.cos(angle),y = height/2 + radius*Math.sin(angle); context.moveTo(x,y); //这里是用来将刻度的另一点指向中心点，并给予正确的角度 //PI是180度，正确的角度就是 angle+180度，正好相反方向 var temp_angle = Math.PI +angle; context.lineTo(x +3*Math.cos(temp_angle),y+3*Math.sin(temp_angle)); context.stroke(); context.closePath(); angle+=6/180*Math.PI; } //大刻度 angle = 0,radius = width/2 - 4; context.textBaseline = 'middle'; context.textAlign = 'center'; context.lineWidth = 2; for(var i=0;i<12;i++){ var num = i+3>12? i+3-12:i+3 ; context.beginPath(); context.strokeStyle="#FFD700"; var x = width/2 + radius*Math.cos(angle),y = height/2 + radius*Math.sin(angle); context.moveTo(x,y); var temp_angle = Math.PI +angle; context.lineTo(x +8*Math.cos(temp_angle),y+8*Math.sin(temp_angle)); context.stroke(); context.closePath(); //大刻度 文字 context.fillText(num,x+16*Math.cos(temp_angle),y+16*Math.sin(temp_angle)); angle+=30/180*Math.PI; } function Pointer(){ var p_type = [['#000',70,1],['#ccc',60,2],['red',50,3]]; function drwePointer(type,angle){ type = p_type[type]; angle = angle*Math.PI*2 - 90/180*Math.PI; var length= type[1]; p_context.beginPath(); p_context.lineWidth = type[2]; p_context.strokeStyle = type[0]; p_context.moveTo(width/2,height/2); p_context.lineTo(width/2 + length*Math.cos(angle),height/2 + length*Math.sin(angle)); p_context.stroke(); p_context.closePath(); } setInterval(function (){ p_context.clearRect(0,0,height,width); var time = new Date(); var h = time.getHours(); var m = time.getMinutes(); var s = time.getSeconds(); h = h>12?h-12:h; h = h+m/60; h=h/12; m=m/60; s=s/60; drwePointer(0,s); drwePointer(1,m); drwePointer(2,h); },500); } var p = new Pointer(); </script></body></html>上述就是小编为大家分享的怎么在html5中实现一个时钟功能了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注编程网行业资讯频道。
