javascript - 使 Arc Canvas 响应

Question

我有两个问题，第一个问题是如何让这个倒计时具有响应性。我尝试使用 Bootstrap 使其具有响应性，但未能达到令人满意的结果。

注意:如果需要，您可以删除我的样式并从头开始。

---

第二个问题发生在当我将圆的半径从 70 更改为任何其他值时，当我更改倒计时圆的半径时，圆将像这样:

代码在这里:

(function($) {
  jQuery.fn.countdown = function(options, callback) {
    var settings = {
      'date': null
    };
    if (options) {
      $.extend(settings, options);
    }
    this_sel = $(this);
    /*Canvas JavaScript*/
    var canvas = document.getElementById('myCanvas');
    var canvas1 = document.getElementById('myCanvas1');
    var canvas2 = document.getElementById('myCanvas2');
    var canvas3 = document.getElementById('myCanvas3');
    var context = canvas.getContext('2d');
    var context1 = canvas1.getContext('2d');
    var context2 = canvas2.getContext('2d');
    var context3 = canvas3.getContext('2d');
    var centerX = canvas.width / 2;
    var centerY = canvas.height / 2;
    var radius = 90;


    var sec_arc_end = 0,
      min_arc_end = 0,
      hour_arc_end = 0,
      day_arc_end = 0;

    function count_exec() {
      eventDate = Date.parse(settings['date']) / 1000;
      currentDate = Math.floor($.now() / 1000);
      if (eventDate <= currentDate) {
        callback.call(this);
        clearInterval(interval);
      }
      seconds = eventDate - currentDate;

      days = Math.floor(seconds / (60 * 60 * 24));

      seconds -= days * 60 * 60 * 24;
      hours = Math.floor(seconds / (60 * 60));
      seconds -= hours * 60 * 60;
      minutes = Math.floor(seconds / 60);
      seconds -= minutes * 60;

      // seconds arc canvas...................
      context.clearRect(50, 50, canvas.width, canvas.height);
      sec_arc_end = ((60 - seconds) * parseFloat(0.10472));
      context.beginPath();
      context.arc(centerX, centerY, radius, 1.5 * Math.PI, 1.5 * Math.PI + sec_arc_end, false);
      context.lineWidth = 8;
      context.strokeStyle = '#14E170';
      context.stroke();

      // minutes arc canvas...................
      context1.clearRect(50, 50, canvas.width, canvas.height);
      min_arc_end = ((60 - minutes) * parseFloat(0.10471));
      context1.beginPath();
      context1.arc(centerX, centerY, radius, 1.5 * Math.PI, 1.5 * Math.PI + min_arc_end, false);
      context1.lineWidth = 8;
      context1.strokeStyle = '#14E170';
      context1.stroke();
        // hours arc canvas...................

      context2.clearRect(50, 50, canvas.width, canvas.height);
      hour_arc_end = ((24 - hours) * parseFloat((0.10471 * 5) / 2));
      context2.beginPath();
      context2.arc(centerX, centerY, radius, 1.5 * Math.PI, 1.5 * Math.PI + hour_arc_end, false);
      context2.lineWidth = 8;
      context2.strokeStyle = '#14E170';
      context2.stroke();
        // days arc canvas...................
      if (days > 364) {
          $('#myCanvas3').hide();
      }
      context3.clearRect(50, 50, canvas.width, canvas.height);
      day_arc_end = ((-days) * parseFloat((0.10471 * 5) / 2));  // the problem is here
      context3.beginPath();
      context3.arc(centerX, centerY, radius, -0.5 * Math.PI, (((365 - days) / 365) * 2 - 0.5) * Math.PI, false);
      context3.lineWidth = 8;
      context3.strokeStyle = '#14E170';
      context3.stroke();
      // add 0 value to left of value
      if (!isNaN(eventDate)) {
        this_sel.find('.days').text(days);
        this_sel.find('.hours').text(hours);
        this_sel.find('.mins').text(minutes);
        this_sel.find('.secs').text(seconds);
      }
    }
    count_exec();
    console.log(days);
    interval = setInterval(count_exec, 1000);


  };
})(jQuery);
$(document).ready(function () {
    $("#countdown").countdown({
        date: "6 january 2018 6:34:00"
    },
      function () {
          $("#countdown").text("merry christmas");
      }
    );
    /*Make Canvas Responsive*/
    $(".countdown-container").height($(".countdown-container").width());
    $(window).resize(function () {
        $(".countdown-container").height($(".countdown-container").width());
    });
})

#countdown {
  width: 100%;
  padding: 5px;
}
.countdown-container {
  width: 24%;
  height: 97%;
  text-align: center;
}
#countdown .countdown-container {
  text-align: center;
  float: left;
  position: relative;
  margin: 0.30% 0.5% 0.30% 0.5%;
}
#countdown .countdown-container .contents {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  margin-right: -50%;
  transform: translate(-50%, -50%);
  font-size-adjust: 0.58;
}
.contents div {
  font-size: 28px;
}
.contents span {
  font-size: 16px;
}
canvas {
  width: 100%;
  height: 100%;
  border:1px solid #06ee7c;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="countdown">
        <div class="countdown-container">
            <div class="contents">
                <div class="secs">
                    00
                </div>
                <span>Seconds</span>
            </div>
            <canvas id="myCanvas" width="250" height="250"></canvas>

        </div>
        <div class="countdown-container">
            <div class="contents">
                <div class="mins">
                    00
                </div>
                <span>Minutes</span>
            </div>
            <canvas id="myCanvas1" width="250" height="250"></canvas>
        </div>
        <div class="countdown-container">
            <div class="contents">
                <div class="hours">
                    00
                </div>
                <span>Hours</span>
            </div>
            <canvas id="myCanvas2" width="250" height="250"></canvas>
        </div>
        <div class="countdown-container">
            <div class="contents">
                <div class="days">
                    00
                </div>
                <span>Days</span>
            </div>
            <canvas id="myCanvas3" width="250" height="250"></canvas>
        </div>
    </div>

注意:

• 请在整页运行代码
• 等待1分钟后每次session出现半径问题

Answer 1

使用 clearRect(0,0,width,height) 代替 clearRect(50,50,width,height)。

(function($) {
	  jQuery.fn.countdown = function(options, callback) {
	    var settings = {
	      'date': null
	    };
	    if (options) {
	      $.extend(settings, options);
	    }
	    this_sel = $(this);
	    /*Canvas JavaScript*/
	    var canvas = document.getElementById('myCanvas');
	    var canvas1 = document.getElementById('myCanvas1');
	    var canvas2 = document.getElementById('myCanvas2');
	    var canvas3 = document.getElementById('myCanvas3');
	    var context = canvas.getContext('2d');
	    var context1 = canvas1.getContext('2d');
	    var context2 = canvas2.getContext('2d');
	    var context3 = canvas3.getContext('2d');
	    var centerX = canvas.width / 2;
	    var centerY = canvas.height / 2;
	    var radius = 90;


	    var sec_arc_end = 0,
	      min_arc_end = 0,
	      hour_arc_end = 0,
	      day_arc_end = 0;

	    function count_exec() {
	      eventDate = Date.parse(settings['date']) / 1000;
	      currentDate = Math.floor($.now() / 1000);
	      if (eventDate <= currentDate) {
	        callback.call(this);
	        clearInterval(interval);
	      }
	      seconds = eventDate - currentDate;

	      days = Math.floor(seconds / (60 * 60 * 24));

	      seconds -= days * 60 * 60 * 24;
	      hours = Math.floor(seconds / (60 * 60));
	      seconds -= hours * 60 * 60;
	      minutes = Math.floor(seconds / 60);
	      seconds -= minutes * 60;

	      // seconds arc canvas...................
	      context.clearRect(0, 0, canvas.width, canvas.height);
	      sec_arc_end = ((60 - seconds) * parseFloat(0.10472));
	      context.beginPath();
	      context.arc(centerX, centerY, radius, 1.5 * Math.PI, 1.5 * Math.PI + sec_arc_end, false);
	      context.lineWidth = 8;
	      context.strokeStyle = '#14E170';
	      context.stroke();
	      // minutes arc canvas...................
	      context1.clearRect(0, 0, canvas.width, canvas.height);
	      min_arc_end = ((60 - minutes) * parseFloat(0.10471));
	      context1.beginPath();
	      context1.arc(centerX, centerY, radius, 1.5 * Math.PI, 1.5 * Math.PI + min_arc_end, false);
	      context1.lineWidth = 8;
	      context1.strokeStyle = '#14E170';
	      context1.stroke();
	        // hours arc canvas...................

	      context2.clearRect(0, 0, canvas.width, canvas.height);
	      hour_arc_end = ((24 - hours) * parseFloat((0.10471 * 5) / 2));
	      context2.beginPath();
	      context2.arc(centerX, centerY, radius, 1.5 * Math.PI, 1.5 * Math.PI + hour_arc_end, false);
	      context2.lineWidth = 8;
	      context2.strokeStyle = '#14E170';
	      context2.stroke();
	        // days arc canvas...................
	      if (days > 364) {
	          $('#myCanvas3').hide();
	      }
	      context3.clearRect(0, 0, canvas.width, canvas.height);
	      day_arc_end = ((-days) * parseFloat((0.10471 * 5) / 2));  // the problem is here
	      context3.beginPath();
	      context3.arc(centerX, centerY, radius, -0.5 * Math.PI, (((365 - days) / 365) * 2 - 0.5) * Math.PI, false);
	      context3.lineWidth = 8;
	      context3.strokeStyle = '#14E170';
	      context3.stroke();
	      // add 0 value to left of value
	      if (!isNaN(eventDate)) {
	        this_sel.find('.days').text(days);
	        this_sel.find('.hours').text(hours);
	        this_sel.find('.mins').text(minutes);
	        this_sel.find('.secs').text(seconds);
	      }
	    }
	    count_exec();
	    console.log(days);
	    interval = setInterval(count_exec, 1000);


	  };
	})(jQuery);
	$(document).ready(function () {
	    $("#countdown").countdown({
	        date: "6 january 2018 6:34:00"
	    },
	      function () {
	          $("#countdown").text("merry christmas");
	      }
	    );
	    /*Make Canvas Responsive*/
	    $(".countdown-container").height($(".countdown-container").width());
	    $(window).resize(function () {
	        $(".countdown-container").height($(".countdown-container").width());
	    });
	})

#countdown {
  width: 100%;
  padding: 5px;
}
.countdown-container {
  width: 24%;
  height: 97%;
  text-align: center;
}
#countdown .countdown-container {
  text-align: center;
  float: left;
  position: relative;
  margin: 0.30% 0.5% 0.30% 0.5%;
}
#countdown .countdown-container .contents {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  margin-right: -50%;
  transform: translate(-50%, -50%);
  font-size-adjust: 0.58;
}
.contents div {
  font-size: 28px;
}
.contents span {
  font-size: 16px;
}
canvas {
  width: 100%;
  height: 100%;
  border:1px solid #06ee7c;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div id="countdown">
        <div class="countdown-container">
            <div class="contents">
                <div class="secs">
                    00
                </div>
                <span>Seconds</span>
            </div>
            <canvas id="myCanvas" width="250" height="250"></canvas>

        </div>
        <div class="countdown-container">
            <div class="contents">
                <div class="mins">
                    00
                </div>
                <span>Minutes</span>
            </div>
            <canvas id="myCanvas1" width="250" height="250"></canvas>
        </div>
        <div class="countdown-container">
            <div class="contents">
                <div class="hours">
                    00
                </div>
                <span>Hours</span>
            </div>
            <canvas id="myCanvas2" width="250" height="250"></canvas>
        </div>
        <div class="countdown-container">
            <div class="contents">
                <div class="days">
                    00
                </div>
                <span>Days</span>
            </div>
            <canvas id="myCanvas3" width="250" height="250"></canvas>
        </div>
    </div>