摘要：代碼如下創建畫布對象開始繪畫微軟雅黑效果如圖使用說明地址

(function(w) {
                function Cycle(options) {
                    this.id = options.id;
                    this.width = options.width;
                    this.height = options.height;
                    this.percent = options.percent;
                    this.border = options.border;
                    this.bgColor = options.bgColor;
                    this.barColor = options.barColor;
                    this.textColor = options.textColor;
                };
                Cycle.prototype = {
                    contructor: Cycle,
                    init: function() {
                        //創建畫布對象
                        var html = "";
                        document.getElementById(this.id).innerHTML = html;
                        var time = setInterval(function() {
                            this.percent++;
                            if(this.percent >= 100) {
                                clearInterval(time);
                            }
                            this.setOptions();
                        }.bind(this), 1000);
                        this.setOptions()
                    },
                    setOptions: function() {
                        var degree = this.percent;
                        var canvas = document.getElementById("canvas_" + this.id);
                        var context = canvas.getContext("2d");
                        context.clearRect(0, 0, this.width, this.height);
                        //開始繪畫
                        context.beginPath();
                        context.lineWidth = this.border;
                        context.strokeStyle = this.bgColor;
                        context.arc(this.width / 2, this.height / 2, (this.width / 2 - this.border / 2), 0, 2 * Math.PI);
                        context.stroke();
                        var deg = degree * 3.6 / 180 * Math.PI
                        context.beginPath();
                        context.lineWidth = this.border;
                        context.strokeStyle = this.barColor;
                        context.arc(this.width / 2, this.height / 2, (this.width / 2 - this.border / 2), 0 - Math.PI / 2, deg - Math.PI / 2);
                        context.stroke();
                        context.beginPath();
                        context.fillStyle = this.textColor;
                        context.font = "18px 微軟雅黑";
                        var text = degree + "%";
                        var textWidth = context.measureText(text).width;
                        context.fillText(text, this.width / 2 - textWidth / 2, this.height / 2 + 9);
                    }
                }
                w.Cycle=Cycle;
            }(window))

使用說明：

var opts1 = {
            id: "cycle1",
            width: "300",
            height: "300",
            percent: "20",
            border: "30",
            bgColor: "green",
            barColor: "yellow",
            textColor: "pink"
        };
        var opts2 = {
            id: "cycle2",
            width: "400",
            height: "400",
            percent: "60",
            border: "30",
            bgColor: "gray",
            barColor: "red",
            textColor: "pink"
        };
        new Cycle(opts1).init();
        new Cycle(opts2).init();

https://github.com/jeromehan/...