Among the choices among many progress bar shapes, everyone will choose the donut chart. So today I will teach you how to use canvas to draw a rounded ring chart and the solution to the blurred progress bar. I hope it will be helpful to you
* @param {type} radius 圆环半径 * @param {type} lineWidth 圆环宽度 * @param {type} strokeStyle 默认背景 * @param {type} fillStyleArray 数组,圆环色块颜色 * @param {type} capType 类型:round是圆角,square正方形顶帽,butt是正常 * @param {type} percentArray ,数字,每个占据的百分比 * @param {type} startAngle 开始的角度 * @param {type} criclex,cricley 圆心坐标,一般是canvas的一半,例如:canvas给的宽度是250,高度是250,那么criclex是125
How to use
var canvas = document.getElementById('canvas'); var ctx = canvas.getContext('2d'); var ring = new Ring("80", "25", "#ccc", ["#a1b91d", "#e9636a", "#e7ba21"], "round"); ring.drawRing(ctx, 2 * Math.PI / 3, [20, 50, 30],125,125);//占据的百分比分别是20%,50%,30%
Source code
The source code is very simple, everyone is welcome to expand!
function Circle(radius, lineWidth, strokeStyle, fillStyleArray, capType) { this.radius = radius; // 圆环半径 this.lineWidth = lineWidth; // 圆环边的宽度 this.strokeStyle = strokeStyle; //边的颜色 this.fillStyle = fillStyleArray; //填充色 this.lineCap = capType;}Circle.prototype.draw = function (ctx,criclex,cricley) { ctx.beginPath(); ctx.arc(criclex, cricley, this.radius, 0, Math.PI * 2, true); // 坐标为90的圆,这里起始角度是0,结束角度是Math.PI*2 ctx.lineWidth = this.lineWidth; ctx.strokeStyle = this.strokeStyle; ctx.stroke(); // 这里用stroke画一个空心圆,想填充颜色的童鞋可以用fill方法};function Ring(radius, lineWidth, strokeStyle, fillStyleArray, capType) { Circle.call(this, radius, lineWidth, strokeStyle, fillStyleArray, capType);}Ring.prototype = Object.create(Circle.prototype);Ring.prototype.drawRing = function (ctx, startAngle, percentArray ,criclex,cricley) { startAngle = startAngle || 3 * Math.PI / 2; percentArray = percentArray || []; this.draw(ctx,criclex,cricley); // 调用Circle的draw方法画圈圈 var _this = this; // angle percentArray.forEach(function (item, index) { ctx.beginPath(); var anglePerSec = 2 * Math.PI / (100 / item); // 蓝色的弧度 ctx.arc(criclex, cricley, _this.radius, startAngle, startAngle + anglePerSec, false); //这里的圆心坐标要和cirle的保持一致 startAngle = startAngle + anglePerSec; ctx.strokeStyle = _this.fillStyle[index]; ctx.lineCap = _this.lineCap; ctx.stroke(); ctx.closePath(); }) //小圆圈覆盖 ctx.beginPath(); ctx.arc(criclex, cricley, _this.radius, startAngle, startAngle, false); //这里的圆心坐标要和cirle的保持一致 ctx.strokeStyle = _this.fillStyle[0]; ctx.lineCap = _this.lineCap; ctx.stroke(); ctx.closePath();}
I believe you have mastered the methods after reading these cases. For more exciting information, please pay attention to other related articles on the php Chinese website!
Related reading:
How to make flying butterflies in CSS3 Animation
How to realize the animation of picture cover display in css3
The above is the detailed content of How to draw a rounded circular shape. For more information, please follow other related articles on the PHP Chinese website!

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