JavaScript实现时钟滴答声效果-tutorial js-php.cn

下面一段代码给大家分享js实现时钟滴答声功能，具体代码如下所示：
<!DOCTYPE html>
<html>
 <head>
 <meta charset="utf8">
 <meta http-equiv="X-UA-Compatible" content="IE=edge, chrome=1">
 <meta name="keywords" content="clock">
 <meta name="description" content="This is a clock">
 <title>Clock</title>
 </head>
 <body>
 <audio id="ticktock">
 <source = src="ticktock.mp3" type="audio/mp3">
 </audio>
 <script type="text/javascript">
 /*
 年(y)可以用 1-4 个占位符
 月(M)、日(d)、时(H,24时)、时(h,12时)、分(m)、秒(s)、季度(q) 可以用 1-2 个占位符
 毫秒(S)只能用 1 个占位符(是 1-3 位数字) 
 AM或PM只能用 1 个占位符(是 2 位英文)
 上午或下午(T)只能用 1 个占位符(是 2 位中文)
 星期(E)可以用 1-3 个占位符
 季度(q)只能用 1 个占位符(是 1 位数字)
 */
 Date.prototype.format = function(fmt) {
 var map = {
  "M+" : this.getMonth() + 1, //月
  "d+" : this.getDate(), //日
  "H+" : this.getHours(), //24时
  /*
  上午12时只代表当天上午的12时,下午的12时代表当天下午的12时,
  0时代表第二天的开始,即前面一天12时已过0时开始计算新一天的时间,
  虽然说时间上跟前面那一天下午12时重合,但日期已经发生更改,所以不能说0时就是12时
  */
  "h+" : this.getHours()%12 == 0 ? 12 : this.getHours()%12,//12时
  "m+" : this.getMinutes(), //分
  "s+" : this.getSeconds(), //秒
  "S" : this.getMilliseconds(), //毫秒
  "t" : this.getHours() < 12 ? "AM" : "PM",
  "T" : this.getHours() < 12 ? "上午" : "下午",
 };
 var week = {
  "0" : "日",
  "1" : "一",
  "2" : "二",
  "3" : "三",
  "4" : "四",
  "5" : "五",
  "6" : "六",
 }
 var quarter = {
  "0" : "一",
  "1" : "二",
  "2" : "三",
  "3" : "四",
 }
 if(/(y+)/.test(fmt)) {
  fmt = fmt.replace(RegExp.$1, (this.getFullYear()+"").substr(4 - RegExp.$1.length));
 }
 if(/(E+)/.test(fmt)) {
  var weekPreStr;
  switch(RegExp.$1.length) {
  case 1:
  weekPreStr = "";
  break;
  case 2:
  weekPreStr = "周";
  break;
  default:
  weekPreStr = "星期";
  break;
  }
  fmt = fmt.replace(RegExp.$1, weekPreStr + week[this.getDay()]);
 }
 if(/(q)/.test(fmt)) {
  fmt = fmt.replace(RegExp.$1, quarter[Math.floor(this.getMonth() / 3)]);
 }
 for(var key in map) {
  if(new RegExp("(" + key + ")").test(fmt)) {
  fmt = fmt.replace(RegExp.$1, RegExp.$1.length == 1 ? map[key] : ("00" + map[key]).substr((map[key]+"").length));
  }
 }
 return fmt;
 }
 </script>
 <script>
 var canvas = document.createElement("canvas");
 document.body.appendChild(canvas);
 var ctx = canvas.getContext("2d");
 var halfPI = Math.PI / 2;
 var doublePI = Math.PI * 2;
 //阴影级别
 var shadowBlur = 10;
 //阴影宽度
 var shadowWidth = 8;
 //阴影在X方向上的偏移
 var shadowOffsetX = 5;
 //阴影在Y方向上的便宜
 var shadowOffsetY = 5;
 //深色阴影
 var shadowDarkColor = "rgba(0,0,0,0.8)";
 //浅色阴影
 var shadowLightColor = "rgba(0,0,0,0.1)";
 //画布中心到边缘的内切圆半径
 var canvasRadius = 250;
 canvas.width = canvasRadius * 2;
 canvas.height = canvasRadius * 2;
 //获取画布中心的坐标
 var cx = canvasRadius;
 var cy = canvasRadius;
 //时钟外圈的贝塞尔花纹个数
 var bezierPatternCount = 36;
 //时钟外圈的贝塞尔花纹波峰处半径
 var bezierPeakRadius = canvasRadius - 10;
 //时钟外圈的贝塞尔花纹一半的角度
 var bezierHalfSpan = doublePI / bezierPatternCount / 2;
 //时钟外圈的贝塞尔花纹底部半径
 var bezierRadius = bezierPeakRadius - 20;
 //时钟外圈的贝塞尔花纹颜色
 var bezierPatternColor = "Plum";
 //时钟外圈半径
 var clockBorderRadius = bezierRadius - 10;
 //时钟外圈宽度
 var clockBorderWidth = 10;
 //时钟外圈颜色
 var clockBorderColor = "Aqua";
 //时钟外圈阴影半径
 var clockBorderShadowRadius = clockBorderRadius - shadowWidth + 1;
 //时钟整数时间刻度线宽
 var clockScaleWidth = 2;
 //时钟整数时间刻度外半径
 var clockScaleOuterRadius = clockBorderRadius - shadowWidth;
 //时钟整数时间刻度内半径
 var clockScaleInnerRadius = clockScaleOuterRadius - 20;
 //时钟刻度颜色
 var clockScaleColor = "Black";
 //时钟非整数时间处半径
 var clockScaleMiddleRadius = clockScaleOuterRadius - 10;
 //时钟数字半径
 var clockNumRadius = clockBorderShadowRadius - 40;
 //时钟数字字体
 var clockNumFont = "25px Arial";
 //时钟数字颜色
 var clockNumColor = "black";
 //数字日期距中心的垂直距离
 var digitalDateMarginCenter = 50;
 //数字日期颜色
 var digitalDateColor = "Black";
 //数字日期字体
 var digitalDateFont = "bold 18px Arial";
 //数字时间距中心的垂直距离
 var digitalTimeMarginCenter = 100;
 //数字时间颜色
 var digitalTimeColor = "white";
 //数字时间背景颜色
 var digitalTimeBgColor = "DarkSlateBlue";
 //数字时间字体
 var digitalTimeFont = "bold 25px Arial";
 //数字时间高度的一半
 var digitalTimeHeight = 40;
 //数字时间分隔线宽度
 var digitalTimeSpanLineWidth = 2;
 //时钟中心点内圆的半径
 var clockCenterInnerDotRadius = 7;
 //时钟中心点内圆的颜色
 var clockCenterInnerDotColor = "FireBrick";
 //时钟中心点外圆的半径
 var clockCenterOuterDotRadius = 10;
 //时钟中心点外圆的颜色
 var clockCenterOuterDotColor = "Maroon";
 //时针线宽
 var clockNeedleWidth = 5;
 //时针半径
 var clockHourNeedleRadius = clockBorderShadowRadius - 120;
 //时针颜色
 var clockHourNeedleColor = "DarkGreen";
 //分针半径
 var clockMinuteNeedleRadius = clockBorderShadowRadius - 80;
 //分针颜色
 var clockMinuteNeedleColor = "DarkSlateGray";
 //秒针半径
 var clockSecondNeedleRadius = clockBorderShadowRadius - 40;
 //秒针尾部半径
 var clockSecondNeedleBottomRadius = -20;
 //秒针颜色
 var clockSecondNeedleColor = "FireBrick";
 //画圆环
 function strokeCircle(cx, cy, r) {
 ctx.beginPath();
 ctx.arc(cx, cy, r, 0, doublePI);
 ctx.stroke();
 }
 //画圆
 function fillCircle(cx, cy, r) {
 ctx.beginPath();
 ctx.arc(cx, cy, r, 0, doublePI);
 ctx.fill();
 }
 //绘制线条
 function strokeLine(x1, y1, x2, y2) {
 ctx.beginPath();
 ctx.moveTo(x1, y1);
 ctx.lineTo(x2, y2);
 ctx.stroke();
 }
 //根据角度和半径计算圆上相应位置的坐标(最右侧为起始角度,顺时针方向为正)
 function circlePos(cx, cy, theta, radius) {
 var pos = {
  x: cx + radius * Math.cos(theta),
  y: cy + radius * Math.sin(theta),
 };
 return pos;
 }
 //在圆环上绘制刻度线
 function strokeCircleLine(cx, cy, theta, r1, r2) {
 var pos1 = circlePos(cx, cy, theta, r1);
 var pos2 = circlePos(cx, cy, theta, r2);
 strokeLine(pos1.x, pos1.y, pos2.x, pos2.y);
 }
 //设置默认阴影
 function setShadow(type) {
 ctx.lineWidth = shadowWidth;
 ctx.shadowBlur = shadowBlur;
 ctx.shadowOffsetX = shadowOffsetX;
 ctx.shadowOffsetY = shadowOffsetY;
 if(type === 1) {
  ctx.shadowColor = shadowLightColor;
 } else {
  ctx.shadowColor = shadowDarkColor;
 }
 }
 //取消阴影
 function clearShadow() {
 ctx.shadowColor = "rgba(0,0,0,0)";
 ctx.shadowBlur = 0;
 ctx.shadowOffsetX = 0;
 ctx.shadowOffsetY = 0;
 }
 //绘制时钟外圈的贝塞尔花纹
 function renderBezierPattern() {
 ctx.fillStyle = bezierPatternColor;
 ctx.beginPath();
 var theta = 0;
 //由于circlePos是顺时针方向正, 故圈也是顺时针方向
 var beginPos = circlePos(cx, cy, theta, bezierRadius);
 ctx.moveTo(beginPos.x, beginPos.y);
 while(theta < doublePI) {
  //贝塞尔曲线控制点
  var controlTheta = theta + bezierHalfSpan;
  var controlPos = circlePos(cx, cy, controlTheta, bezierPeakRadius);
  //贝塞尔曲线终止点
  var endTheta = controlTheta + bezierHalfSpan;
  var endPos = circlePos(cx, cy, endTheta, bezierRadius);
  ctx.quadraticCurveTo(controlPos.x, controlPos.y, endPos.x, endPos.y);
  theta = endTheta;
 }
 //绘制圆counterclockwise=false, 即默认是顺时针方向
 ctx.arc(cx, cy, clockBorderRadius, 0, doublePI, true);
 //注意: 两个相反方向的路径内部为填充范围
 ctx.fill();
 }
 //绘制时钟边框
 function renderClockBorder() {
 //画外框
 ctx.strokeStyle = clockBorderColor;
 ctx.lineWidth = clockBorderWidth;
 strokeCircle(cx, cy, clockBorderRadius);
 //画外框的内阴影
 ctx.strokeStyle = shadowLightColor;
 setShadow(1);
 strokeCircle(cx, cy, clockBorderShadowRadius);
 clearShadow();
 }
 //绘制时钟圆周上的数字和刻度部分
 function renderClockNums() {
 ctx.textAlign = "center";
 ctx.textBaseline = "middle";
 ctx.font = clockNumFont;
 var span = doublePI / 60;
 for(var i = 1, radian = -halfPI + span; i <= 60; i++, radian += span) {
  if(i % 5 == 0) {
  //绘制刻度
  ctx.strokeStyle = clockScaleColor;
  ctx.lineWidth = clockScaleWidth;
  strokeCircleLine(cx, cy, radian, clockScaleInnerRadius, clockScaleOuterRadius);
  //绘制数字
  var pos = circlePos(cx, cy, radian, clockNumRadius);
  var num = i / 5;
  ctx.fillStyle = clockNumColor;
  ctx.fillText(num, pos.x, pos.y);
  } else {
  ctx.strokeStyle = clockScaleColor;
  ctx.lineWidth = clockScaleWidth;
  strokeCircleLine(cx, cy, radian, clockScaleMiddleRadius, clockScaleOuterRadius);
  }
 }
 }
 //绘制数字时钟
 function renderDigital(date) {
 //绘制日期
 ctx.textAlign = "center";
 ctx.textBaseline = "middle";
 ctx.font = digitalDateFont;
 ctx.fillStyle = digitalDateColor;
 var text = date.format("yyyy年MM月dd日 EEE");
 ctx.fillText(text, cx, cy + digitalDateMarginCenter);
 //绘制时间
 ctx.font = digitalTimeFont;
 text = date.format(" HH mm ss ");
 ctx.fillStyle = digitalTimeBgColor;
 var textWidth = ctx.measureText(text).width;
 var textBgX = cx - textWidth / 2;
 var textBgY = cy + digitalTimeMarginCenter - digitalTimeHeight / 2;
 ctx.fillRect(textBgX, textBgY, textWidth, digitalTimeHeight);
 ctx.fillStyle = digitalTimeColor;
 ctx.fillText(text, cx, cy + digitalTimeMarginCenter);
 //绘制事件中间的分隔线
 ctx.lineWidth = digitalTimeSpanLineWidth;
 ctx.strokeStyle = digitalTimeColor;
 var textSpan = textWidth / 6;
 var leftLineX = cx - textSpan;
 strokeLine(leftLineX, textBgY, leftLineX, textBgY + digitalTimeHeight);
 var rightLineX = cx + textSpan;
 strokeLine(rightLineX, textBgY, rightLineX, textBgY + digitalTimeHeight);
 }
 //绘制时钟中心最下方红点
 function renderClockCenterOuterDot() {
 ctx.fillStyle = clockCenterOuterDotColor;
 fillCircle(cx, cy, clockCenterOuterDotRadius);
 }
 //绘制时钟中心最上方红点
 function renderClockCenterInnerDot() {
 ctx.fillStyle = clockCenterInnerDotColor;
 fillCircle(cx, cy, clockCenterInnerDotRadius);
 }
 //绘制时钟指针
 function renderClockNeedle(date) {
 var hourRadian = date.getHours() % 12 / 12 * doublePI - halfPI;
 var minuteRadian = date.getMinutes() / 60 * doublePI - halfPI;
 var secondRadian = date.getSeconds() / 60 * doublePI - halfPI;
 setShadow();
 ctx.lineCap = "round";
 ctx.lineWidth = clockNeedleWidth;
 ctx.strokeStyle = clockHourNeedleColor;
 strokeCircleLine(cx, cy, hourRadian, 0, clockHourNeedleRadius);
 ctx.strokeStyle = clockMinuteNeedleColor;
 strokeCircleLine(cx, cy, minuteRadian, 0, clockMinuteNeedleRadius);
 ctx.strokeStyle = clockSecondNeedleColor;
 strokeCircleLine(cx, cy, secondRadian, clockSecondNeedleBottomRadius, clockSecondNeedleRadius);
 ctx.lineCap = "square";
 clearShadow();
 }
 function render(date) {
 ctx.clearRect(0, 0, canvas.width, canvas.height);
 renderBezierPattern();
 renderClockBorder();
 renderClockNums();
 renderDigital(date);
 renderClockCenterOuterDot();
 renderClockNeedle(date);
 renderClockCenterInnerDot();
 }
 var lastTime = 0;
 var audio = document.getElementById("ticktock");
 function loop() {
 var date = new Date();
 var currentTime = date.getTime();
 if(currentTime - lastTime >= 1000) {
  lastTime = currentTime;
  //注意：这里设0非常关键，否则虽然会循环播放，但会从上一次暂停的地方开始播放，造成延迟
  audio.currentTime = 0;
  audio.play();
  render(date);
 }
 requestAnimationFrame(loop);
 }
 loop();
 </script>
 </body>
</html>
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JavaScript实现时钟滴答声效果