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[js高手之路] html5 canvas教程,html5canvas

[js高手之路] html5 canvas教程,html5canvas效果图: 这个实例主要注意: 1,剩余时间的计算 2,每个时间数字的绘制 时间主要有0-9和一个冒号组成,用数组来表示( 0...

[js高手之路] html5 canvas教程,html5canvas

效果图:

这个实例主要注意:

1,剩余时间的计算

2,每个时间数字的绘制

时间主要有0-9和一个冒号组成,用数组来表示( 0: 就是不画圆,1:就是画一个蓝色的圆 )

num.js文件:

1 var digital = 2 [ 3 [ 4 [0,0,1,1,1,0,0], 5 [0,1,1,0,1,1,0], 6 [1,1,0,0,0,1,1], 7 [1,1,0,0,0,1,1], 8 [1,1,0,0,0,1,1], 9 [1,1,0,0,0,1,1], 10 [1,1,0,0,0,1,1], 11 [1,1,0,0,0,1,1], 12 [0,1,1,0,1,1,0], 13 [0,0,1,1,1,0,0] 14 ],//0 15 [ 16 [0,0,0,1,1,0,0], 17 [0,1,1,1,1,0,0], 18 [0,0,0,1,1,0,0], 19 [0,0,0,1,1,0,0], 20 [0,0,0,1,1,0,0], 21 [0,0,0,1,1,0,0], 22 [0,0,0,1,1,0,0], 23 [0,0,0,1,1,0,0], 24 [0,0,0,1,1,0,0], 25 [1,1,1,1,1,1,1] 26 ],//1 27 [ 28 [0,1,1,1,1,1,0], 29 [1,1,0,0,0,1,1], 30 [0,0,0,0,0,1,1], 31 [0,0,0,0,1,1,0], 32 [0,0,0,1,1,0,0], 33 [0,0,1,1,0,0,0], 34 [0,1,1,0,0,0,0], 35 [1,1,0,0,0,0,0], 36 [1,1,0,0,0,1,1], 37 [1,1,1,1,1,1,1] 38 ],//2 39 [ 40 [1,1,1,1,1,1,1], 41 [0,0,0,0,0,1,1], 42 [0,0,0,0,1,1,0], 43 [0,0,0,1,1,0,0], 44 [0,0,1,1,1,0,0], 45 [0,0,0,0,1,1,0], 46 [0,0,0,0,0,1,1], 47 [0,0,0,0,0,1,1], 48 [1,1,0,0,0,1,1], 49 [0,1,1,1,1,1,0] 50 ],//3 51 [ 52 [0,0,0,0,1,1,0], 53 [0,0,0,1,1,1,0], 54 [0,0,1,1,1,1,0], 55 [0,1,1,0,1,1,0], 56 [1,1,0,0,1,1,0], 57 [1,1,1,1,1,1,1], 58 [0,0,0,0,1,1,0], 59 [0,0,0,0,1,1,0], 60 [0,0,0,0,1,1,0], 61 [0,0,0,1,1,1,1] 62 ],//4 63 [ 64 [1,1,1,1,1,1,1], 65 [1,1,0,0,0,0,0], 66 [1,1,0,0,0,0,0], 67 [1,1,1,1,1,1,0], 68 [0,0,0,0,0,1,1], 69 [0,0,0,0,0,1,1], 70 [0,0,0,0,0,1,1], 71 [0,0,0,0,0,1,1], 72 [1,1,0,0,0,1,1], 73 [0,1,1,1,1,1,0] 74 ],//5 75 [ 76 [0,0,0,0,1,1,0], 77 [0,0,1,1,0,0,0], 78 [0,1,1,0,0,0,0], 79 [1,1,0,0,0,0,0], 80 [1,1,0,1,1,1,0], 81 [1,1,0,0,0,1,1], 82 [1,1,0,0,0,1,1], 83 [1,1,0,0,0,1,1], 84 [1,1,0,0,0,1,1], 85 [0,1,1,1,1,1,0] 86 ],//6 87 [ 88 [1,1,1,1,1,1,1], 89 [1,1,0,0,0,1,1], 90 [0,0,0,0,1,1,0], 91 [0,0,0,0,1,1,0], 92 [0,0,0,1,1,0,0], 93 [0,0,0,1,1,0,0], 94 [0,0,1,1,0,0,0], 95 [0,0,1,1,0,0,0], 96 [0,0,1,1,0,0,0], 97 [0,0,1,1,0,0,0] 98 ],//7 99 [ 100 [0,1,1,1,1,1,0], 101 [1,1,0,0,0,1,1], 102 [1,1,0,0,0,1,1], 103 [1,1,0,0,0,1,1], 104 [0,1,1,1,1,1,0], 105 [1,1,0,0,0,1,1], 106 [1,1,0,0,0,1,1], 107 [1,1,0,0,0,1,1], 108 [1,1,0,0,0,1,1], 109 [0,1,1,1,1,1,0] 110 ],//8 111 [ 112 [0,1,1,1,1,1,0], 113 [1,1,0,0,0,1,1], 114 [1,1,0,0,0,1,1], 115 [1,1,0,0,0,1,1], 116 [0,1,1,1,0,1,1], 117 [0,0,0,0,0,1,1], 118 [0,0,0,0,0,1,1], 119 [0,0,0,0,1,1,0], 120 [0,0,0,1,1,0,0], 121 [0,1,1,0,0,0,0] 122 ],//9 123 [ 124 [0,0,0,0], 125 [0,0,0,0], 126 [0,1,1,0], 127 [0,1,1,0], 128 [0,0,0,0], 129 [0,0,0,0], 130 [0,1,1,0], 131 [0,1,1,0], 132 [0,0,0,0], 133 [0,0,0,0] 134 ]//: 135 ]; View Code

倒计时实现:

 1 <head>
 2     <meta charset=‘utf-8‘ />
 3     <style>
 4         #canvas {
 5             border: 1px dashed #aaa;
 6         }
 7     </style>
 8     <script src="./num.js"></script>
 9     <script>
10         window.onload = function () {
11             var oCanvas = document.querySelector("#canvas"),
12                 oGc = oCanvas.getContext(‘2d‘),
13                 width = oCanvas.width, height = oCanvas.height,
14                 radius = 10,
15                 leftTime = 0,
16                 endTime = new Date( 2017, 09, 10, 15, 30, 02 );
17             
18             leftTime = getLeftTime();
19             showTime( oGc );
20             setInterval(function(){
21                 oGc.clearRect( 0, 0, width, height );
22                 leftTime = getLeftTime();
23                 showTime( oGc );
24             }, 1000);
25 
26             function showTime( cxt ){
27                 var hour = parseInt( leftTime / 3600 );
28                 var min = parseInt( ( leftTime - hour * 3600 ) / 60 );
29                 var sec = leftTime % 60;
30 
31                 showNum( 0, 0, parseInt( hour / 10 ), cxt );
32                 showNum( 15 * ( radius + 1 ), 0, parseInt( hour % 10 ), cxt );
33                 showNum( 30 * ( radius + 1 ), 0, 10, cxt );
34                 showNum( 39 * ( radius + 1 ), 0, parseInt( min / 10 ), cxt );
35                 showNum( 54 * ( radius + 1 ), 0, parseInt( min % 10 ), cxt );
36                 showNum( 69 * ( radius + 1 ), 0, 10, cxt );
37                 showNum( 78 * ( radius + 1 ), 0, parseInt( sec / 10 ), cxt );
38                 showNum( 93 * ( radius + 1 ), 0, parseInt( sec % 10 ), cxt );
39             }
40 
41             function getLeftTime(){
42                 var curTime = new Date();
43                 var restTime = endTime.getTime() - curTime.getTime();
44                 restTime = Math.round( restTime / 1000 );
45                 return restTime > 0 ? restTime : 0;
46             }
47 
48             //显示时间的每一位
49             function showNum( x, y, num, cxt ){
50                 cxt.fillStyle = ‘#09f‘;
51                 for( var i = 0; i < digital[num].length; i++ ){
52                     for( var j = 0; j < digital[num][i].length; j++ ){
53                         if ( digital[num][i][j] == 1 ){
54                             cxt.beginPath();
55                             cxt.arc( x + j * 2 * ( radius + 1 ) + ( radius + 1 ), y + i * 2 * ( radius + 1 ) + ( radius + 1 ), radius, 0, + 360 * Math.PI / 180, false );
56                             cxt.closePath();
57                             cxt.fill();
58                         }
59                     }
60                 }
61             }
62         }
63     </script>
64 </head>
65 <body>
66     <canvas id="canvas" width="1200" height="300"></canvas>
67 </body>


这里要注意一下,如果当前时间超过2017年10月10日15:30:02分就没有效果了,你需要把这个剩余时间设置比你当前的时间大几天就可以了

http://www.bkjia.com/HTML5/1228805.htmlwww.bkjia.comtruehttp://www.bkjia.com/HTML5/1228805.htmlTechArticle[js高手之路] html5 canvas教程,html5canvas 效果图: 这个实例主要注意: 1,剩余时间的计算 2,每个时间数字的绘制 时间主要有0-9和一个冒号组...