HTMl5实现可缩放时钟代码分析

HTMl5实现可缩放时钟代码分析

废话不多说了,直接给大家贴代码了,具体代码如下所示:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>canvas_time</title>
  <style type="text/css">
  div {
    text-align: center;
    margin-top: 250px;
  }
  #clock {
    border: 1px solid #cccccc;
  }
  </style>
</head>
<body>
  <div>
    <canvas id="clock" height="600px" width="600px"></canvas>
  </div>
  <script type="text/JavaScript" >
var dom = document.getElementById('clock');
var ctx = dom.getContext('2d');
var width = ctx.canvas.width;
var height = ctx.canvas.height;
var r = width / 2;
var rem = width/200;
function drawBackground() {
  ctx.save(); //存储当前环境变量;
  ctx.translate(r, r); //重置坐标到r,r
  ctx.beginPath(); // 起始一条路径
  ctx.lineWidth = 10*rem; //设置线宽10;
  ctx.arc(0, 0, r - ctx.lineWidth /2, 0, 2 * Math.PI, false);
  ctx.stroke();
  var hourNumbers = [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2]; //定义数组
  ctx.font = 18*rem+"px Arial";
  ctx.textAlign = "center";
  ctx.textBaseline = "middle";
    hourNumbers.forEach(function(number, i) {
    var rad = 2 * Math.PI / 12 * i;
    var x = Math.cos(rad) * (r - 30*rem);
    var y = Math.sin(rad) * (r - 30*rem);
    ctx.fillText(number, x, y);
  });
  for (var i = 0; i < 60; i++) {
    var rad = 2 * Math.PI / 60 * i;
    var x = Math.cos(rad) * (r - 18*rem);
    var y = Math.sin(rad) * (r - 18*rem);
    ctx.beginPath();
    if (i % 5 === 0) {
      ctx.arc(x, y, 2*rem, 0, 2 * Math.PI, false);
      ctx.fillStyle = "#000";
    } else {
      ctx.arc(x, y, 2*rem, 0, 2 * Math.PI, false);
      ctx.fillStyle = "#ccc";
    }
    ctx.fill();
  }
}
  function drawHour(hour, minute) {
    ctx.save();
    ctx.beginPath();
    var rad = 2 * Math.PI / 12 * hour;
    var mrad = 2 * Math.PI / 12 / 60 * minute;
    ctx.rotate(rad + mrad);
    ctx.lineWidth = 6*rem;
    ctx.lineCap = "round";
    ctx.moveTo(0, 10*rem);
    ctx.lineTo(0, -r / 2);
    ctx.stroke();
    ctx.restore();
  }
  function drawMinute(minute) {
    ctx.save();
    ctx.beginPath();
    var rad = 2 * Math.PI / 60 * minute;
    ctx.rotate(rad);
    ctx.lineWidth = 3*rem;
    ctx.lineCap = "round";
    ctx.moveTo(0, 10*rem);
    ctx.lineTo(0, -r + 30*rem);
    ctx.stroke();
    ctx.restore();
  }
  function drawSecond(second) {
    ctx.save();
    ctx.beginPath();
    ctx.fillStyle = 'red';
    var rad = 2 * Math.PI / 60 * second;
    ctx.rotate(rad);
    ctx.moveTo(-2*rem, 20*rem);
    ctx.lineTo(2*rem, 20*rem);
    ctx.lineTo(1, -r + 16*rem);
    ctx.lineTo(-1, -r + 16*rem);
    ctx.fill();
    ctx.restore();
  }
  function drawDot() {
    ctx.beginPath();
    ctx.fillStyle = '#fff';
    ctx.arc(0, 0, 3*rem, 0, 2 * Math.PI, false);
    ctx.fill();
  }
  function draw01() {
    ctx.clearRect(0, 0, width, height);
    var now = new Date();
    var hour = now.getHours();
    var minute = now.getMinutes();
    var second = now.getSeconds();
    drawBackground();
    drawHour(hour, minute);
    drawMinute(minute);
    drawSecond(second);
    drawDot();
    ctx.restore();
  }
  draw01();
  setInterval(draw01, 1000);
</script>
</body>
</html>

总结

以上所述是小编给大家介绍的HTML5实现可缩放时钟代码,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对路饭网站的支持!