function toCanvas(id ,progress){ canvas进度条
var canvas = document.getElementById(id),
ctx = canvas.getContext("2d"),
percent = progress, 最终百分比 circleX = canvas.width / 2, 中心x坐标 circleY = canvas.height / 2, 中心y坐标 radius = 100, 圆环半径 lineWidth = 5, 圆形线条的宽度 fontSize = 20; 字体大小
两端圆点
function smallcircle1(cx, cy, r) {
ctx.beginPath(); //ctx.moveTo(cx + r, cy); ctx.lineWidth = 1;
ctx.fillStyle = '#06a8f3';
ctx.arc(cx, cy, r,0,Math.PI*2);
ctx.fill();
} function smallcircle2(cx, cy, r) {
ctx.beginPath(); //ctx.moveTo(cx + r, cy); ctx.lineWidth = 1;
ctx.fillStyle = '#00f8bb';
ctx.arc(cx, cy, r,0,Math.PI*2);
ctx.fill();
} 画圆
function circle(cx, cy, r) {
ctx.beginPath(); //ctx.moveTo(cx + r, cy); ctx.lineWidth = lineWidth;
ctx.strokeStyle = '#eee';
ctx.arc(cx, cy, r, Math.PI*2/3, Math.PI * 1/3);
ctx.stroke();
} 画弧线
function sector(cx, cy, r, startAngle, endAngle, anti) {
ctx.beginPath(); //ctx.moveTo(cx, cy + r); // 从圆形底部开始画 ctx.lineWidth = lineWidth; // 渐变色 - 可自定义
var linGrad = ctx.createLinearGradient(
circleX-radius-lineWidth, circleY, circleX+radius+lineWidth, circleY
);
linGrad.addColorStop(0.0, '#06a8f3'); //linGrad.addColorStop(0.5, '#9bc4eb'); linGrad.addColorStop(1.0, '#00f8bb');
ctx.strokeStyle = linGrad; 圆弧两端的样式 ctx.lineCap = 'round'; 圆弧 ctx.arc(
cx, cy, r,
(Math.PI*2/3), (Math.PI*2/3) + endAngle/100 * (Math.PI*5/3),
false
);
ctx.stroke();
} 刷新
function loading() { if (process >= percent) {
clearInterval(circleLoading);
} 清除canvas内容 ctx.clearRect(0, 0, circleX * 2, circleY * 2); 中间的字 ctx.font = fontSize + 'px April';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.fillStyle = '#999';
ctx.fillText(parseFloat(process).toFixed(0) + '%', circleX, circleY);
圆形 circle(circleX, circleY, radius);
圆弧 sector(circleX, circleY, radius, Math.PI*2/3, process);
两端圆点 smallcircle1(150+Math.cos(2*Math.PI/360*120)*100, 150+Math.sin(2*Math.PI/360*120)*100, 5);
smallcircle2(150+Math.cos(2*Math.PI/360*(120+process*3))*100, 150+Math.sin(2*Math.PI/360*(120+process*3))*100, 5); 控制结束时动画的速度
if (process / percent > 0.90) {
process += 0.30;
} else if (process / percent > 0.80) {
process += 0.55;
} else if (process / percent > 0.70) {
process += 0.75;
} else {
process += 1.0;
}
} var process = 0.0; 进度
var circleLoading = window.setInterval(function () {
loading();
}, 20);
}
第二部分，调用封装好的代码：
toCanvas('canvas',50);
