canvas实例

使用原生canvas做钟表实例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>钟表</title>
    <style>
        canvas{
            position: absolute;
            left:10;
            top:10;
        }
    </style>
</head>
<body>
    <canvas id="dial_canvas"></canvas>
    <canvas id="hand_canvas"></canvas>

    <script>
        var w = 800;  //画布宽度
        var h = 600;  //画布高度
        var r = 200;  //表的半径

        var dial_canvas = document.getElementById("dial_canvas");  //获取表盘canvasdom
        var hand_canvas = document.getElementById("hand_canvas");  //获取指针canvasdom

        dial_canvas.width = w;
        dial_canvas.height = h;
        hand_canvas.width = w;
        hand_canvas.height = h;

        var dial_cxt = dial_canvas.getContext("2d"); //获取表盘绘图环境
        var hand_cxt = hand_canvas.getContext("2d"); //获取指针绘图环境

        //绘制表盘
        dial_cxt.beginPath();
        dial_cxt.arc(w/2, h/2, r, 0, Math.PI*2);
        dial_cxt.lineWidth = 10;
        dial_cxt.strokeStyle = "#000";
        dial_cxt.stroke();

        //绘制刻度 小时 (大刻度)
        drawScale(dial_cxt, w/2, h/2, r, r-20, 12, 10);

        //绘制刻度 分钟(小刻度)
        drawScale(dial_cxt, w/2, h/2, r, r-10, 60, 2);


        //定时绘制指针
        function run(){
            var date = new Date(); //时间对象

            //清空画布
            hand_cxt.clearRect(0,0,w,h);

            //获取秒
            var seconds = date.getSeconds();
            drawHand(hand_cxt, w/2, h/2, seconds / 60 * 360, 180, 2, "red");
            
            //分针
            var minutes = date.getMinutes() + seconds / 60;
            drawHand(hand_cxt, w/2, h/2, minutes / 60 * 360, 150, 5, "#000");

            //时针
            var hours = date.getHours() % 12 + minutes / 60;
            drawHand(hand_cxt, w/2, h/2, hours / 12 * 360, 120, 8, "#000");

            setTimeout(run, 1000);
        }
        run();


        /**
         * 绘制指针
         * @param object cxt 绘图环境
         * @param number x 表中心的x坐标
         * @param number y 表中心的y坐标
         * @param number angle 指针旋转的角度
         * @param number length 指针长度
         * @param number lineWidth 指针宽度
         * @param string  strokeStyle 指针颜色
        */
        function drawHand(cxt, x, y, angle, length, lineWidth=8, strokeStyle="#000") {

            cxt.save(); //保存环境

            cxt.beginPath(); //开启路径

            cxt.translate(x, y);
            cxt.rotate((angle - 90)/180 * Math.PI);

            cxt.moveTo(-20, 0);
            cxt.lineTo(length, 0);

            cxt.lineWidth = lineWidth;
            cxt.strokeStyle = strokeStyle;
            cxt.stroke();

            cxt.restore(); //恢复环境
        }

        /**
         * 绘制刻度
         * @param object cxt 绘图环境
         * @param number x 圆心x坐标
         * @param number y 圆心y坐标
         * @param number innerRadius 内圆的半径
         * @param number outerRadius 外圆的半径
         * @param int   number 刻度的个数
         * @param number lineWidth 刻度的宽度
         * @param string strokeStyle 刻度的颜色  
        */
        function drawScale(cxt,x,y,innerRadius,outerRadius, number = 12, lineWidth = 10, strokeStyle = "#000"){

            var angle = 0;
            var angleDiff = 360 / number;  //间隔的度数
            
            for (var i = 0; i < number; i ++) {
                var x1 = Math.cos(angle / 180 * Math.PI) * outerRadius + w/2;
                var y1 = Math.sin(angle / 180 * Math.PI) * outerRadius + h/2;
                var x2 = Math.cos(angle / 180 * Math.PI) * innerRadius + w/2;
                var y2 = Math.sin(angle / 180 * Math.PI) * innerRadius + h/2;

                cxt.beginPath();
                cxt.moveTo(x1, y1);
                cxt.lineTo(x2, y2);
                cxt.lineWidth = lineWidth;
                cxt.strokeStyle = strokeStyle               
                cxt.stroke();
                angle += angleDiff;
            }
        }



    </script>
    
</body>
</html>

使用canvas库做钟表实例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <div id="box"></div>

    <script src="../bower_components/konva/konva.min.js"></script>
    <script>
        //设置变量
        var w = 800;
        var h = 600;
        var r = 200;

        //创建舞台
        var stage = new Konva.Stage({
            width:w,
            height:h,
            container:"box"
        })

        //创建表盘层
        var dialLayer = new Konva.Layer();
        stage.add(dialLayer);

        //绘制表盘
        var dialCircle = new Konva.Circle({
            x:w/2,
            y:h/2,
            radius:r,
            stroke:"#000",
            strokeWidth:10,
            fill:"#eee"
        })
        dialLayer.add(dialCircle);

        //绘制刻度
        var bigDialScale = new DialScale({
            x:w/2,
            y:h/2,
            outerRadius:r,
            innerRadius:r-20,
            stroke:"#000",
            strokeWidth:10,
            number:12
        });
        dialLayer.add(bigDialScale);

        //绘制小刻度
        var smallScale = new DialScale({
            x:w/2,
            y:h/2,
            outerRadius:r,
            innerRadius:r-10,
            stroke:"#000",
            strokeWidth:2,
            number:60
        });
        dialLayer.add(smallScale);

        //绘制
        dialLayer.draw();


        //创建指针层
        var handLayer = new Konva.Layer();
        stage.add(handLayer);

        //秒针
        var secondHand = new Konva.Line({
            x:w/2,
            y:h/2,
            points:[-20,0,180,0],
            stroke:"red",
            strokeWidth:"2",
            rotation:0
        });
        handLayer.add(secondHand);


        //分针
        var minuteHand = new Konva.Line({
            x:w/2,
            y:h/2,
            points:[-20,0,150,0],
            stroke:"#000",
            strokeWidth:"5",
            rotation:0
        });
        handLayer.add(minuteHand);


        //时针
        var hourHand = new Konva.Line({
            x:w/2,
            y:h/2,
            points:[-20,0,120,0],
            stroke:"#000",
            strokeWidth:"8",
            rotation:0
        });
        handLayer.add(hourHand);


        var centerCirle = new Konva.Circle({
            x:w/2,
            y:h/2,
            radius:10,
            fill:"#000"
        })
        handLayer.add(centerCirle);



        //绘制指针层
        handLayer.draw();


        function run(){
            var date = new Date();

            //秒针转动
            var seconds = date.getSeconds();
            secondHand.rotation(seconds/60 * 360 - 90);

            //分针转动
            var minutes = date.getMinutes() + seconds / 60;
            minuteHand.rotation(minutes/60 * 360 - 90);

            //时针转动
            var hours = date.getHours() % 12 + minutes / 60;
            hourHand.rotation(hours / 12 * 360 - 90);

            handLayer.draw(); //重新绘制


            setTimeout(run, 1000);
        }
        run();


        /**
         * 生成表盘刻度的构造函数
         * @params object options 配置项
        */
        function DialScale(options) {
            options = options || {};
            options.x = options.x || 0;
            options.y = options.y || 0;
            options.outerRadius = options.outerRadius || 0;
            options.innerRadius = options.innerRadius || 0;
            options.number = options.number || 12;
            options.strokeWidth = options.strokeWidth || 10;
            options.stroke = options.stroke || "#000";

            //创建组
            var group = new Konva.Group({
                x:options.x,
                y:options.y
            });

            //循环绘制刻度, 并且添加到组中
            var angle = 0;
            var angleDiff = 360 / options.number;
            for (var i = 0; i < options.number; i ++) {

                var line = new Konva.Line({
                    points:[Math.cos(angle / 180 * Math.PI) * options.outerRadius,
                            Math.sin(angle / 180 * Math.PI) * options.outerRadius,
                            Math.cos(angle / 180 * Math.PI) * options.innerRadius,
                            Math.sin(angle / 180 * Math.PI) * options.innerRadius
                            ],
                    stroke:options.stroke,
                    strokeWidth:options.strokeWidth
                });
                group.add(line);

                angle += angleDiff;
            }


            return group;
        }



    </script>
</body>
</html>

太阳系实例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <div id="box"></div>
    <script src="../bower_components/konva/konva.js"></script>
    <script>

        var stage = new Konva.Stage({
            container:"box",
            width:window.innerWidth,
            height:window.innerHeight
        });

        //定义变量
        var cx = 400;
        var cy = 400;
        var bigRadius = 240;
        var middleRadius = 160;
        var centerRadius = 80;

        //创建背景层
        var bgLayer = new Konva.Layer();
        stage.add(bgLayer);

        //大圈
        var bigCircle = new Konva.Circle({
            x:cx,
            y:cy,
            radius:bigRadius,
            stroke:"#ccc",
            dash:[10,2]
        });
        bgLayer.add(bigCircle);

        //中圈
        var middleCircle = new Konva.Circle({
            x:cx,
            y:cy,
            radius:middleRadius,
            stroke:"#ccc",
            dash:[10,2]
        });
        bgLayer.add(middleCircle);

        //中心
        var centerCircle = new CircleText({
            x:cx,
            y:cy,
            innerRadius:centerRadius,
            outerRadius:centerRadius+30,
            innerFill:"#369",
            outerFill:"#ddd",
            text:"WEB前端",
            fontSize:18,
            fontWeight:"bold",
            fontFill:"#fff",
            fontX:-35,
            fontY:-9

        });
        bgLayer.add(centerCircle);

        bgLayer.draw();

        //创建动画层
        var layer = new Konva.Layer();
        stage.add(layer);

        //最外圈的小球
        var bigCircleData = [
            {
                innerRadius:40,
                outerRadius:50,
                innerFill:"#5cb85c",
                outerFill:"#ddd",
                text:"HTML5",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            },
            {
                innerRadius:40,
                outerRadius:50,
                innerFill:"#5bc0de",
                outerFill:"#ddd",
                text:"CSS3",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            },
            {
                innerRadius:40,
                outerRadius:50,
                innerFill:"#f0ad4e",
                outerFill:"#ddd",
                text:"ECMA6",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            },
            {
                innerRadius:40,
                outerRadius:50,
                innerFill:"#d9534f",
                outerFill:"#ddd",
                text:"jQuery",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            },
            {
                innerRadius:40,
                outerRadius:50,
                innerFill:"#428bca",
                outerFill:"#ddd",
                text:"NodeJS",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            }
        ];

        //创建一个组
        var bigCircleGroup = new Konva.Group({
            x:cx,
            y:cy
        });
        layer.add(bigCircleGroup); //把组添加到层中

        var angle = 0;
        var angleDiff = 360 / bigCircleData.length;

        bigCircleData.forEach(function(option, index){
            
            option.x = Math.cos(angle / 180 * Math.PI) * bigRadius;
            option.y = Math.sin(angle / 180 * Math.PI) * bigRadius;
            var circleText = new CircleText(option);

            bigCircleGroup.add(circleText); //添加到组中

            angle += angleDiff;

        });

        //绘制 中间圈的小球
        //定义数据
        var middleCircleData = [
            {
                innerRadius:30,
                outerRadius:40,
                innerFill:"purple",
                outerFill:"#ddd",
                text:"VueJS",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            },
            {
                innerRadius:30,
                outerRadius:40,
                innerFill:"pink",
                outerFill:"#ddd",
                text:"Angle",
                fontSize:14,
                fontX:-20,
                fontY:-7,
                opacity:.7
            }
        ]

        //创建组
        var middleCircleGroup = new Konva.Group({
            x:cx,
            y:cy
        });
        layer.add(middleCircleGroup);

        //添加小圆圈
        var angle1 = 0;
        var angleDiff1 = 360 / middleCircleData.length;

        middleCircleData.forEach(function(option, index){
            
            option.x = Math.cos(angle1 / 180 * Math.PI) * middleRadius;
            option.y = Math.sin(angle1 / 180 * Math.PI) * middleRadius;
            var circleText = new CircleText(option);

            middleCircleGroup.add(circleText); //添加到组中

            angle1 += angleDiff1;

        });

        layer.draw();

        //两个圈 要转
        var angleSpeed = 60; //每秒钟转的角度
        var animation = new Konva.Animation(function(frame){
            var angleDiff = angleSpeed * frame.timeDiff / 1000;
            //外圈转动
            bigCircleGroup.rotate(angleDiff);
            bigCircleGroup.getChildren().each(function(val, index){
                val.rotate(-angleDiff);
            }) 

            //内圈转动
            middleCircleGroup.rotate(-angleDiff);
            middleCircleGroup.getChildren().each(function(val, index){
                val.rotate(angleDiff);
            }) 

        }, layer);
        animation.start();

        //事件
        bigCircleGroup.on("mouseenter", function(){
            angleSpeed = 10;
        }).on("mouseleave touchend", function(){
            angleSpeed = 60;
        })


        /**
         * 生成带文字的双层圆
        */
        function CircleText(options) {
            //配置项
            options = options || {};
            options.x = options.x || 0;
            options.y = options.y || 0;
            options.innerRadius = options.innerRadius || 0;
            options.outerRadius = options.outerRadius || 0;
            options.innerFill = options.innerFill || "red";
            options.outerFill = options.outerFill || "#ddd";
            options.text = options.text || "小萍萍";
            options.fontFill = options.fontFill || "#fff";
            options.fontSize = options.fontSize || 16;
            options.fontWeight = options.fontWeight || "normal";
            options.fontFamily = options.fontFamily || "MicrosoftYaHei";
            options.fontX = options.fontX || 0;
            options.fontY = options.fontY || 0;
            options.opacity = options.opacity || 1;

            //创建组
            var group = new Konva.Group({
                x:options.x,
                y:options.y
            })

            //最中心的实心圆
            var circle = new Konva.Circle({
                x:0,
                y:0,
                radius:options.innerRadius,
                fill:options.innerFill
            });
            group.add(circle);

            //空心圆 圆环
            var ring = new Konva.Ring({
                x:0,
                y:0,
                innerRadius:options.innerRadius,
                outerRadius:options.outerRadius,
                fill:options.outerFill
            });
            group.add(ring);

            //文字
            var text = new Konva.Text({
                x:options.fontX,
                y:options.fontY,
                text:options.text,
                fill:options.fontFill,
                fontSize:options.fontSize,
                fontFamily:options.fontFamily,
                fontWeight:options.fontWeight
            });
            group.add(text);
            return group;
        }
    </script>
</body>
</html>
最后编辑于
©著作权归作者所有,转载或内容合作请联系作者
  • 序言:七十年代末,一起剥皮案震惊了整个滨河市,随后出现的几起案子,更是在滨河造成了极大的恐慌,老刑警刘岩,带你破解...
    沈念sama阅读 160,108评论 4 364
  • 序言:滨河连续发生了三起死亡事件,死亡现场离奇诡异,居然都是意外死亡,警方通过查阅死者的电脑和手机,发现死者居然都...
    沈念sama阅读 67,699评论 1 296
  • 文/潘晓璐 我一进店门,熙熙楼的掌柜王于贵愁眉苦脸地迎上来,“玉大人,你说我怎么就摊上这事。” “怎么了?”我有些...
    开封第一讲书人阅读 109,812评论 0 244
  • 文/不坏的土叔 我叫张陵,是天一观的道长。 经常有香客问我,道长,这世上最难降的妖魔是什么? 我笑而不...
    开封第一讲书人阅读 44,236评论 0 213
  • 正文 为了忘掉前任,我火速办了婚礼,结果婚礼上,老公的妹妹穿的比我还像新娘。我一直安慰自己,他们只是感情好,可当我...
    茶点故事阅读 52,583评论 3 288
  • 文/花漫 我一把揭开白布。 她就那样静静地躺着,像睡着了一般。 火红的嫁衣衬着肌肤如雪。 梳的纹丝不乱的头发上,一...
    开封第一讲书人阅读 40,739评论 1 222
  • 那天,我揣着相机与录音,去河边找鬼。 笑死,一个胖子当着我的面吹牛,可吹牛的内容都是我干的。 我是一名探鬼主播,决...
    沈念sama阅读 31,957评论 2 315
  • 文/苍兰香墨 我猛地睁开眼,长吁一口气:“原来是场噩梦啊……” “哼!你这毒妇竟也来了?” 一声冷哼从身侧响起,我...
    开封第一讲书人阅读 30,704评论 0 204
  • 序言:老挝万荣一对情侣失踪,失踪者是张志新(化名)和其女友刘颖,没想到半个月后,有当地人在树林里发现了一具尸体,经...
    沈念sama阅读 34,447评论 1 246
  • 正文 独居荒郊野岭守林人离奇死亡,尸身上长有42处带血的脓包…… 初始之章·张勋 以下内容为张勋视角 年9月15日...
    茶点故事阅读 30,643评论 2 249
  • 正文 我和宋清朗相恋三年,在试婚纱的时候发现自己被绿了。 大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
    茶点故事阅读 32,133评论 1 261
  • 序言:一个原本活蹦乱跳的男人离奇死亡,死状恐怖,灵堂内的尸体忽然破棺而出,到底是诈尸还是另有隐情,我是刑警宁泽,带...
    沈念sama阅读 28,486评论 3 256
  • 正文 年R本政府宣布,位于F岛的核电站,受9级特大地震影响,放射性物质发生泄漏。R本人自食恶果不足惜,却给世界环境...
    茶点故事阅读 33,151评论 3 238
  • 文/蒙蒙 一、第九天 我趴在偏房一处隐蔽的房顶上张望。 院中可真热闹,春花似锦、人声如沸。这庄子的主人今日做“春日...
    开封第一讲书人阅读 26,108评论 0 8
  • 文/苍兰香墨 我抬头看了看天上的太阳。三九已至,却和暖如春,着一层夹袄步出监牢的瞬间,已是汗流浃背。 一阵脚步声响...
    开封第一讲书人阅读 26,889评论 0 197
  • 我被黑心中介骗来泰国打工, 没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留,地道东北人。 一个月前我还...
    沈念sama阅读 35,782评论 2 277
  • 正文 我出身青楼,却偏偏与公主长得像,于是被迫代替她去往敌国和亲。 传闻我的和亲对象是个残疾皇子,可洞房花烛夜当晚...
    茶点故事阅读 35,681评论 2 272

推荐阅读更多精彩内容