JS實現滑動拼圖驗證功能完整示例
阿新 • • 發佈:2020-04-02
本文例項講述了JS實現滑動拼圖驗證功能。分享給大家供大家參考,具體如下:
先看一下效果圖:
設定畫布滑塊屬性
const l = 42,// 滑塊邊長 r = 10,// 滑塊半徑 w = 310,// canvas寬度 h = 155,// canvas高度 PI = Math.PI const L = l + r * 2 // 滑塊實際邊長
設定背景圖片:
圖片連結地址可以自行更換
function getRandomImg() { return 'https://picsum.photos/300/150/?image=' + getRandomNumberByRange(0,100) }
CSS部分程式碼:
.container { width: 310px; margin: 100px auto; } #msg { width: 100%; line-height: 40px; font-size: 14px; text-align: center; } a:link,a:visited,a:hover,a:active { margin-left: 100px; color: #0366D6; } .block { position: absolute; left: 0; top: 0; } .sliderContainer { position: relative; text-align: center; width: 310px; height: 40px; line-height: 40px; margin-top: 15px; background: #f7f9fa; color: #45494c; border: 1px solid #e4e7eb; } .sliderContainer_active .slider { height: 38px; top: -1px; border: 1px solid #1991FA; } .sliderContainer_active .sliderMask { height: 38px; border-width: 1px; } .sliderContainer_success .slider { height: 38px; top: -1px; border: 1px solid #52CCBA; background-color: #52CCBA !important; } .sliderContainer_success .sliderMask { height: 38px; border: 1px solid #52CCBA; background-color: #D2F4EF; } .sliderContainer_success .sliderIcon { background-position: 0 0 !important; } .sliderContainer_fail .slider { height: 38px; top: -1px; border: 1px solid #f57a7a; background-color: #f57a7a !important; } .sliderContainer_fail .sliderMask { height: 38px; border: 1px solid #f57a7a; background-color: #fce1e1; } .sliderContainer_fail .sliderIcon { background-position: 0 -83px !important; } .sliderContainer_active .sliderText,.sliderContainer_success .sliderText,.sliderContainer_fail .sliderText { display: none; } .sliderMask { position: absolute; left: 0; top: 0; height: 40px; border: 0 solid #1991FA; background: #D1E9FE; } .slider { position: absolute; top: 0; left: 0; width: 40px; height: 40px; background: #fff; box-shadow: 0 0 3px rgba(0,0.3); cursor: pointer; transition: background .2s linear; } .slider:hover { background: #1991FA; } .slider:hover .sliderIcon { background-position: 0 -13px; } .sliderIcon { position: absolute; top: 15px; left: 13px; width: 14px; height: 10px; background: url(img/tb.png) 0 -26px; background-size: 34px 471px; } .refreshIcon { position: absolute; right: 0; top: 0; width: 34px; height: 34px; cursor: pointer; background: url(img/tb.png) 0 -437px; background-size: 34px 471px; }
頁面,頁面只用放一個div就可以了
<div class="container"> <div id="captcha" style="position: relative"></div> </div>
js部分程式碼,包括驗證是否正確
<script type="text/javascript"> (function(window) { const l = 42,// 滑塊邊長 r = 10,// 滑塊半徑 w = 310,// canvas寬度 h = 155,// canvas高度 PI = Math.PI const L = l + r * 2 // 滑塊實際邊長 function getRandomNumberByRange(start,end) { return Math.round(Math.random() * (end - start) + start) } function createCanvas(width,height) { const canvas = createElement('canvas') canvas.width = width canvas.height = height return canvas } function createImg(onload) { const img = createElement('img') img.crossOrigin = "Anonymous" img.onload = onload img.onerror = () => { img.src = getRandomImg() } img.src = getRandomImg() return img } function createElement(tagName) { return document.createElement(tagName) } function addClass(tag,className) { tag.classList.add(className) } function removeClass(tag,className) { tag.classList.remove(className) } function getRandomImg() { return 'https://picsum.photos/300/150/?image=' + getRandomNumberByRange(0,100) } function draw(ctx,operation,x,y) { ctx.beginPath() ctx.moveTo(x,y) ctx.lineTo(x + l / 2,y) ctx.arc(x + l / 2,y - r + 2,r,2 * PI) ctx.lineTo(x + l / 2,y) ctx.lineTo(x + l,y + l / 2) ctx.arc(x + l + r - 2,y + l / 2,2 * PI) ctx.lineTo(x + l,y + l / 2) ctx.lineTo(x + l,y + l) ctx.lineTo(x,y) ctx.fillStyle = '#fff' ctx[operation]() ctx.beginPath() ctx.arc(x,1.5 * PI,0.5 * PI) ctx.globalCompositeOperation = "xor" ctx.fill() } function sum(x,y) { return x + y } function square(x) { return x * x } class jigsaw { constructor(el,success,fail) { this.el = el this.success = success this.fail = fail } init() { this.initDOM() this.initImg() this.draw() this.bindEvents() } initDOM() { const canvas = createCanvas(w,h) // 畫布 const block = canvas.cloneNode(true) // 滑塊 const sliderContainer = createElement('div') const refreshIcon = createElement('div') const sliderMask = createElement('div') const slider = createElement('div') const sliderIcon = createElement('span') const text = createElement('span') block.className = 'block' sliderContainer.className = 'sliderContainer' refreshIcon.className = 'refreshIcon' sliderMask.className = 'sliderMask' slider.className = 'slider' sliderIcon.className = 'sliderIcon' text.innerHTML = '向右滑動滑塊填充拼圖' text.className = 'sliderText' const el = this.el el.appendChild(canvas) el.appendChild(refreshIcon) el.appendChild(block) slider.appendChild(sliderIcon) sliderMask.appendChild(slider) sliderContainer.appendChild(sliderMask) sliderContainer.appendChild(text) el.appendChild(sliderContainer) Object.assign(this,{ canvas,block,sliderContainer,refreshIcon,slider,sliderMask,sliderIcon,text,canvasCtx: canvas.getContext('2d'),blockCtx: block.getContext('2d') }) } initImg() { const img = createImg(() => { this.canvasCtx.drawImage(img,w,h) this.blockCtx.drawImage(img,h) const y = this.y - r * 2 + 2 const ImageData = this.blockCtx.getImageData(this.x,y,L,L) this.block.width = L this.blockCtx.putImageData(ImageData,y) }) this.img = img } draw() { // 隨機建立滑塊的位置 this.x = getRandomNumberByRange(L + 10,w - (L + 10)) this.y = getRandomNumberByRange(10 + r * 2,h - (L + 10)) draw(this.canvasCtx,'fill',this.x,this.y) draw(this.blockCtx,'clip',this.y) } clean() { this.canvasCtx.clearRect(0,h) this.blockCtx.clearRect(0,h) this.block.width = w } bindEvents() { this.el.onselectstart = () => false this.refreshIcon.onclick = () => { this.reset() } let originX,originY,trail = [],isMouseDown = false this.slider.addEventListener('mousedown',function(e) { originX = e.x,originY = e.y isMouseDown = true }) document.addEventListener('mousemove',(e) => { if(!isMouseDown) return false const moveX = e.x - originX const moveY = e.y - originY if(moveX < 0 || moveX + 38 >= w) return false this.slider.style.left = moveX + 'px' var blockLeft = (w - 40 - 20) / (w - 40) * moveX this.block.style.left = blockLeft + 'px' addClass(this.sliderContainer,'sliderContainer_active') this.sliderMask.style.width = moveX + 'px' trail.push(moveY) }) document.addEventListener('mouseup',(e) => { if(!isMouseDown) return false isMouseDown = false if(e.x == originX) return false removeClass(this.sliderContainer,'sliderContainer_active') this.trail = trail const { spliced,TuringTest } = this.verify() if(spliced) { if(TuringTest) { addClass(this.sliderContainer,'sliderContainer_success') this.success && this.success() } else { addClass(this.sliderContainer,'sliderContainer_fail') this.text.innerHTML = '再試一次' this.reset() } } else { alert("驗證失敗"); addClass(this.sliderContainer,'sliderContainer_fail') this.fail && this.fail(); //驗證失敗後,1秒後重新載入圖片 setTimeout(() => { this.reset() },1000) } }) } verify() { const arr = this.trail // 拖動時y軸的移動距離 const average = arr.reduce(sum) / arr.length // 平均值 const deviations = arr.map(x => x - average) // 偏差陣列 const stddev = Math.sqrt(deviations.map(square).reduce(sum) / arr.length) // 標準差 const left = parseInt(this.block.style.left) return { spliced: Math.abs(left - this.x) < 10,TuringTest: average !== stddev,// 只是簡單的驗證拖動軌跡,相等時一般為0,表示可能非人為操作 } } reset() { this.sliderContainer.className = 'sliderContainer' this.slider.style.left = 0 this.block.style.left = 0 this.sliderMask.style.width = 0 this.clean() this.img.src = getRandomImg() this.draw() } } window.jigsaw = { init: function(element,fail) { new jigsaw(element,fail).init() } } }(window)) jigsaw.init(document.getElementById('captcha'),function() { alert("驗證成功"); }) </script>
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希望本文所述對大家JavaScript程式設計有所幫助。