设计自己的神奇小彩带，你只需这几步：
- 点开博客园后台
- 点开设置
- 找到“页首 HTML 代码”（页尾也可以）
- 输入代码保存即可
- （要先申请js权限哦）
代码如下：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> </body> <script async="" type="text/javascript"> (function (name, factory) { if (typeof window === "object") { window[name] = factory(); } })("Ribbons", function () { var _w = window, _b = document.body, _d = document.documentElement; var random = function () { if (arguments.length === 1) { if (Array.isArray(arguments[0])) { var index = Math.round(random(0, arguments[0].length - 1)); return arguments[0][index]; } return random(0, arguments[0]); } else if (arguments.length === 2) { return Math.random() * (arguments[1] - arguments[0]) + arguments[0]; } return 0; }; var screenInfo = function (e) { var width = Math.max(0, _w.innerWidth || _d.clientWidth || _b.clientWidth || 0), height = Math.max(0, _w.innerHeight || _d.clientHeight || _b.clientHeight || 0), scrollx = Math.max(0, _w.pageXOffset || _d.scrollLeft || _b.scrollLeft || 0) - (_d.clientLeft || 0), scrolly = Math.max(0, _w.pageYOffset || _d.scrollTop || _b.scrollTop || 0) - (_d.clientTop || 0); return { width, height: height, ratio: width / height, centerx: width / 2, centery: height / 2, scrollx: scrollx, scrolly: scrolly }; }; var mouseInfo = function (e) { var screen = screenInfo(e), mousex = e ? Math.max(0, e.pageX || e.clientX || 0) : 0, mousey = e ? Math.max(0, e.pageY || e.clientY || 0) : 0; return { mousex: mousex, mousey: mousey, centerx: mousex - screen.width / 2, centery: mousey - screen.height / 2 }; }; var Point = function (x, y) { this.x = 0; this.y = 0; this.set(x, y); }; Point.prototype = { constructor: Point, set: function (x, y) { this.x = x || 0; this.y = y || 0; }, copy: function (point) { this.x = point.x || 0; this.y = point.y || 0; return this; }, multiply: function (x, y) { this.x *= x || 1; this.y *= y || 1; return this; }, divide: function (x, y) { this.x /= x || 1; this.y /= y || 1; return this; }, add: function (x, y) { this.x += x || 0; this.y += y || 0; return this; }, subtract: function (x, y) { this.x -= x || 0; this.y -= y || 0; return this; }, clampX: function (min, max) { this.x = Math.max(min, Math.min(this.x, max)); return this; }, clampY: function (min, max) { this.y = Math.max(min, Math.min(this.y, max)); return this; }, flipX: function () { this.x *= -1; return this; }, flipY: function () { this.y *= -1; return this; } }; var Factory = function (options) { this._canvas = null; this._context = null; this._sto = null; this._width = 0; this._height = 0; this._scroll = 0; this._ribbons = []; this._options = { colorSaturation: "80%", colorBrightness: "60%", colorAlpha: 0.65, colorCycleSpeed: 6, verticalPosition: "center", horizontalSpeed: 200, ribbonCount: 4, strokeSize: 0, parallaxAmount: -0.5, animateSections: true }; this._onDraw = this._onDraw.bind(this); this._onResize = this._onResize.bind(this); this._onScroll = this._onScroll.bind(this); this.setOptions(options); this.init(); }; Factory.prototype = { constructor: Factory, setOptions: function (options) { if (typeof options === "object") { for (var key in options) { if (options.hasOwnProperty(key)) { this._options[key] = options[key]; } } } }, init: function () { try { this._canvas = document.createElement("canvas"); this._canvas.style["display"] = "block"; this._canvas.style["position"] = "fixed"; this._canvas.style["margin"] = "0"; this._canvas.style["padding"] = "0"; this._canvas.style["border"] = "0"; this._canvas.style["outline"] = "0"; this._canvas.style["left"] = "0"; this._canvas.style["top"] = "0"; this._canvas.style["width"] = "100%"; this._canvas.style["height"] = "100%"; this._canvas.style["z-index"] = "-1"; this._canvas.style["background-color"] = "#1f1f1f"; this._canvas.id = "bgCanvas"; this._onResize(); this._context = this._canvas.getContext("2d"); this._context.clearRect(0, 0, this._width, this._height); this._context.globalAlpha = this._options.colorAlpha; // 这里可以设置是否随着窗口的滚动而滚动 window.addEventListener("resize", this._onResize); window.addEventListener("scroll", this._onScroll); // 这里设置添加的位置 var body_ = document.getElementsByTagName('body')[0]; body_.appendChild(this._canvas); } catch (e) { console.warn("Canvas Context Error: " + e.toString()); return; } this._onDraw(); }, addRibbon: function () { var dir = Math.round(random(1, 9)) > 5 ? "right" : "left", stop = 1000, hide = 200, min = 0 - hide, max = this._width + hide, movex = 0, movey = 0, startx = dir === "right" ? min : max, starty = Math.round(random(0, this._height)); if (/^(top|min)$/i.test(this._options.verticalPosition)) { starty = 0 + hide; } else if (/^(middle|center)$/i.test(this._options.verticalPosition)) { starty = this._height / 2; } else if (/^(bottom|max)$/i.test(this._options.verticalPosition)) { starty = this._height - hide; } var ribbon = [], point1 = new Point(startx, starty), point2 = new Point(startx, starty), point3 = null, color = Math.round(random(0, 360)), delay = 0; while (true) { if (stop <= 0) break; stop--; movex = Math.round((Math.random() * 1 - 0.2) * this._options.horizontalSpeed); movey = Math.round((Math.random() * 1 - 0.5) * (this._height * 0.25)); point3 = new Point(); point3.copy(point2); if (dir === "right") { point3.add(movex, movey); if (point2.x >= max) break; } else if (dir === "left") { point3.subtract(movex, movey); if (point2.x <= min) break; } ribbon.push({ point1: new Point(point1.x, point1.y), point2: new Point(point2.x, point2.y), point3: point3, color: color, delay: delay, dir: dir, alpha: 0, phase: 0 }); point1.copy(point2); point2.copy(point3); delay += 4; color += this._options.colorCycleSpeed; } this._ribbons.push(ribbon); }, _drawRibbonSection: function (section) { if (section) { if (section.phase >= 1 && section.alpha <= 0) { return true; } if (section.delay <= 0) { section.phase += 0.02; section.alpha = Math.sin(section.phase) * 1; section.alpha = section.alpha <= 0 ? 0 : section.alpha; section.alpha = section.alpha >= 1 ? 1 : section.alpha; if (this._options.animateSections) { var mod = Math.sin(1 + section.phase * Math.PI / 2) * 0.1; if (section.dir === "right") { section.point1.add(mod, 0); section.point2.add(mod, 0); section.point3.add(mod, 0); } else { section.point1.subtract(mod, 0); section.point2.subtract(mod, 0); section.point3.subtract(mod, 0); } section.point1.add(0, mod); section.point2.add(0, mod); section.point3.add(0, mod); } } else { section.delay -= 0.5; } var s = this._options.colorSaturation, l = this._options.colorBrightness, c = "hsla(" + section.color + ", " + s + ", " + l + ", " + section.alpha + " )"; this._context.save(); if (this._options.parallaxAmount !== 0) { this._context.translate(0, this._scroll * this._options.parallaxAmount); } this._context.beginPath(); this._context.moveTo(section.point1.x, section.point1.y); this._context.lineTo(section.point2.x, section.point2.y); this._context.lineTo(section.point3.x, section.point3.y); this._context.fillStyle = c; this._context.fill(); if (this._options.strokeSize > 0) { this._context.lineWidth = this._options.strokeSize; this._context.strokeStyle = c; this._context.lineCap = "round"; this._context.stroke(); } this._context.restore(); } return false; }, _onDraw: function () { for (var i = 0, t = this._ribbons.length; i < t; ++i) { if (!this._ribbons[i]) { this._ribbons.splice(i, 1); } } this._context.clearRect(0, 0, this._width, this._height); for (var a = 0; a < this._ribbons.length; ++a) { var ribbon = this._ribbons[a], numSections = ribbon.length, numDone = 0; for (var b = 0; b < numSections; ++b) { if (this._drawRibbonSection(ribbon[b])) { numDone++; } } if (numDone >= numSections) { this._ribbons[a] = null; } } if (this._ribbons.length < this._options.ribbonCount) { this.addRibbon(); } requestAnimationFrame(this._onDraw); }, _onResize: function (e) { var screen = screenInfo(e); this._width = screen.width; this._height = screen.height; if (this._canvas) { this._canvas.width = this._width; this._canvas.height = this._height; if (this._context) { this._context.globalAlpha = this._options.colorAlpha; } } }, _onScroll: function (e) { var screen = screenInfo(e); this._scroll = screen.scrolly; } }; return Factory; }); new Ribbons(); </script> </html>
效果图：
