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使用canvas绘制时钟

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使用canvas绘制时钟 1. [文件] clock.html~3KB 下载 (11) !doctype htmlhtml lang="en" head meta charset="UTF-8" meta name="Description" content="" titlecanvas时钟/title /head bodycanvas id="canvas" width="300" height="300"/canvasscr
使用canvas绘制时钟

1. [文件] clock.html ~ 3KB     下载(11)    

<!doctype html>
<html lang="en">
 <head>
  <meta charset="UTF-8">
  <meta name="Description" content="">
  <title>canvas时钟</title>
 </head>
 <body>
	<canvas id="canvas" width="300" height="300"></canvas>
	<script>
		var canvas=document.getElementById("canvas");
		var context=canvas.getContext('2d');
		//draw();
		function draw(){
			//得到当前系统的时分秒
			var now=new Date();
			var sec=now.getSeconds();
			var min=now.getMinutes();
			var hour=now.getHours();
			hour>=12&&(hour=hour-12);

			
			var radius = Math.min(canvas.width/2,canvas.height/2);
			//初始化画布
			context.save();
			context.clearRect(0,0,canvas.width,canvas.height);
			 context.translate(canvas.width/2,canvas.height/2); 
			context.rotate(-Math.PI/2);
			context.save();
	
			//表框
			

			//小时刻度
			context.strokeStyle="black";
			context.fillStyle="black";
			context.lineWidth=3;
			context.lineCap="round";
			context.beginPath();
			for(var i=0;i<12;i++){
				context.rotate(Math.PI/6);
				context.moveTo(radius-30,0);
				context.lineTo(radius-10,0);

			}
			context.stroke();
			context.restore();
			context.save();

			//分钟刻度
			context.lineWidth=2;
			context.beginPath();
			for(var i=0;i<60;i++){
				if(!i%5==0){
				context.moveTo(radius-15,0);
				context.lineTo(radius-10,0);
				}
				context.rotate(Math.PI/30);
			}
			context.stroke();
			context.restore();
			context.save();

			//画上时针

			 context.rotate((Math.PI/6)*hour+(Math.PI/360)*min+(Math.PI/21600)*sec);
			 context.lineWidth=6;
			 context.beginPath();
			 context.moveTo(-10,0);
			 context.lineTo(radius*0.5,0);
			 context.stroke();
			context.restore();
			context.save();

			 context.rotate((Math.PI/30)*min+(Math.PI/1800)*sec);
      context.strokeStyle="#29A8DE";
      context.lineWidth=4;
      context.lineCap="butt";
      context.beginPath();
      context.moveTo(-20,0);
      context.lineTo(radius*0.7,0);
      context.stroke();
      context.restore();
      context.save();

	  context.rotate(sec*Math.PI/30);
      context.strokeStyle="red";
      context.lineWidth=2;
      context.lineCap="butt";
      context.beginPath();
      context.moveTo(-30,0);
      context.lineTo(radius*0.9,0);
      context.stroke();
      context.restore();
      context.save();

		   context.lineWidth=4;
			 context.strokeStyle="gray";
			context.beginPath();
				 context.arc(0,0,radius,0,Math.PI*2,true);
		  context.stroke();
		  context.restore();


		  context.restore();
		}

		window.onload=function(){
			setInterval(draw,1000)
		}
	</script>
 </body>
</html>

2. [代码][JavaScript]代码    

<script>
		var canvas=document.getElementById("canvas");
		var context=canvas.getContext('2d');
		//draw();
		function draw(){
			//得到当前系统的时分秒
			var now=new Date();
			var sec=now.getSeconds();
			var min=now.getMinutes();
			var hour=now.getHours();
			hour>=12&&(hour=hour-12);

			
			var radius = Math.min(canvas.width/2,canvas.height/2);
			//初始化画布
			context.save();
			context.clearRect(0,0,canvas.width,canvas.height);
			 context.translate(canvas.width/2,canvas.height/2); 
			context.rotate(-Math.PI/2);
			context.save();
	
			//表框
			

			//小时刻度
			context.strokeStyle="black";
			context.fillStyle="black";
			context.lineWidth=3;
			context.lineCap="round";
			context.beginPath();
			for(var i=0;i<12;i++){
				context.rotate(Math.PI/6);
				context.moveTo(radius-30,0);
				context.lineTo(radius-10,0);

			}
			context.stroke();
			context.restore();
			context.save();

			//分钟刻度
			context.lineWidth=2;
			context.beginPath();
			for(var i=0;i<60;i++){
				if(!i%5==0){
				context.moveTo(radius-15,0);
				context.lineTo(radius-10,0);
				}
				context.rotate(Math.PI/30);
			}
			context.stroke();
			context.restore();
			context.save();

			//画上时针

			 context.rotate((Math.PI/6)*hour+(Math.PI/360)*min+(Math.PI/21600)*sec);
			 context.lineWidth=6;
			 context.beginPath();
			 context.moveTo(-10,0);
			 context.lineTo(radius*0.5,0);
			 context.stroke();
			context.restore();
			context.save();

			 context.rotate((Math.PI/30)*min+(Math.PI/1800)*sec);
      context.strokeStyle="#29A8DE";
      context.lineWidth=4;
      context.lineCap="butt";
      context.beginPath();
      context.moveTo(-20,0);
      context.lineTo(radius*0.7,0);
      context.stroke();
      context.restore();
      context.save();

	  context.rotate(sec*Math.PI/30);
      context.strokeStyle="red";
      context.lineWidth=2;
      context.lineCap="butt";
      context.beginPath();
      context.moveTo(-30,0);
      context.lineTo(radius*0.9,0);
      context.stroke();
      context.restore();
      context.save();

		   context.lineWidth=4;
			 context.strokeStyle="gray";
			context.beginPath();
				 context.arc(0,0,radius,0,Math.PI*2,true);
		  context.stroke();
		  context.restore();


		  context.restore();
		}

		window.onload=function(){
			setInterval(draw,1000)
		}
	</script>
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