javascript canvas实现简易时钟例子


本文实例为大家分享了javascript canvas实现简易时钟的具体代码,供大家参考,具体内容如下

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>钟表</title>
  <script type="text/javascript">
  window.onload=function(){
    //1.获取画布
    var canvas=document.getElementById("canvas");
    //2.获取上下文对象(获取画笔)
    var cx=canvas.getContext("2d");
    //3.设置画笔样式
    function clock(){
      cx.fillStyle="tomato";
    //4.绘制图形
      //绘制表盘
      cx.beginPath(); //绘制圆形
      cx.arc(300,300,200,0,Math.PI*2);//设置圆 arc(x,y,r,begin,end,c);x,y:圆的圆的圆心坐标 r:圆的半径 begin,end:开始角度和结束角度;Math.PI=180 Math.PI/180=1度 c:是否按照逆时针进行绘制true:按照逆时 false:顺时针
      cx.closePath();//关闭路径
      cx.fill();//
      //绘制时刻度
        cx.lineWidth=2;
        cx.strokeStyle="black";
        for(var i=0;i<12;i++){
          cx.save();
          cx.translate(300,300);//形移
          cx.rotate(i*(Math.PI/6));
          
          cx.beginPath();
          cx.moveTo(0,-180);
          cx.lineTo(0,-200);
          cx.stroke();
          cx.closePath();

          cx.fillStyle="black";//绘制数字
          cx.font="16px blod";
          cx.rotate(Math.PI/6);
          cx.fillText(i+1,-6,-220);//文字

          cx.restore();
        }

      //绘制分刻度
      for(var i=0;i<60;i++){
        cx.save();
        cx.translate(300,300);
        cx.rotate(i*(Math.PI/30));

        cx.beginPath();
        cx.moveTo(0,-190);
        cx.lineTo(0,-200);
        cx.stroke();
        cx.closePath();

        cx.restore();
      }
      
      //获取当前时间
      var today=new Date();
      var hour=today.getHours();
      var min=today.getMinutes();
      var sec=today.getSeconds();

      hour=hour+min/60;
      
      //绘制时针
      cx.lineWidth=4;
      cx.save();
      cx.translate(300,300);
      cx.beginPath();
      cx.rotate(hour*(Math.PI/6));//旋转
      cx.moveTo(0,10);
      cx.lineTo(0,-130);
      cx.closePath();
      cx.stroke();
      cx.restore();   //回滚

      //绘制分针
      cx.lineWidth=2;
      cx.save();
      cx.translate(300,300);
      cx.beginPath();
      cx.rotate(min*(Math.PI/30));
      cx.moveTo(0,10);
      cx.lineTo(0,-160);
      cx.closePath();
      cx.stroke();
      cx.restore();   //回滚

      //绘制秒针
      cx.lineWidth=1;
      cx.strokeStyle="black";
      cx.save();
      cx.translate(300,300);
      cx.beginPath();
      cx.rotate(sec*(Math.PI/30));
      cx.moveTo(0,10);
      cx.lineTo(0,-160);
      cx.closePath();
      cx.stroke();
      cx.restore();  

      //绘制交叉处
      cx.fillStyle='#ccc';
      cx.strokeStyle="red";
      cx.save();
      cx.translate(300,300);
      cx.beginPath();
      cx.beginPath();
      cx.arc(0,0,4,0,Math.PI*2);
      cx.closePath();
      cx.fill();
      cx.closePath();
      cx.stroke();
      cx.restore();
      
      setTimeout(clock,1000);
    }
   
    // setInterval(clock,1000);
    clock();
  }
  </script>
</head>
<body>
  <canvas id="canvas" width="1300px" height="600px" style="background-color: #ccc;"></canvas>
</body>
</html>

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持来客网。


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