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緣由:之前看嗶哩嗶哩官網登錄的時候有一個拼圖驗證碼,很好奇怎么去實現。然后就想著自己弄一個。先給大家看我的最終效果。后面再一點點拆解代碼。
為什么想著寫這個功能呢,主要在于拼圖驗證碼在前端這里會比較復雜并且深入。相比文字拼寫,12306的圖片驗證碼都沒有拼圖驗證碼對前端的要求來的復雜,和難。
我總結下知識點:
1、彈窗功能
2、彈窗基于元素定位
3、元素拖動
4、canvas繪圖
5、基礎邏輯
一、彈窗和彈窗組件
抱歉,這里我偷懶了直接用了elementUI的el-popover組件,所以小伙伴不懂的直接看elementUI官網的說明。
我個人也研究和編寫了這塊的組件功能(基于popper.js)
二、編寫基礎結構
這塊屬于html的基礎內容,也就標題黨了
三、canvas繪制圖片
1、canvas繪制外部img圖片
代碼:
let mainDom = document.querySelector("#codeImg"); let bg = mainDom.getContext("2d"); let width = mainDom.width; let height = mainDom.height; let blockDom = document.querySelector("#sliderBlock"); let block = blockDom.getContext("2d"); //重新賦值,讓canvas進行重新繪制 blockDom.height = height; mainDom.height = height; let imgsrc = require("../assets/images/back.jpg"); let img = document.createElement("img"); img.style.objectFit = "scale-down"; img.src = imgsrc; img.onload = function() { bg.drawImage(img, 0, 0, width, height); block.drawImage(img, 0, 0, width, height); };
這里我繪制了兩個canvas,因為一個是背景一個是滑塊
核心在于
let mainDom = document.querySelector("#codeImg"); let imgsrc = require("../assets/images/back.jpg"); let bg = mainDom.getContext("2d"); let img = document.createElement("img"); img.onload = function() { bg.drawImage(img, 0, 0, width, height); };
2、canvas繪制滑塊部分
就是這個圖,這個有一些知識點,不難,但是很復雜。
具體請看:https://www.w3school.com.cn/tags/html_ref_canvas.asp
代碼部分:
drawBlock(ctx, xy = { x: 254, y: 109, r: 9 }, type) { let x = xy.x, y = xy.y, r = xy.r, w = 40; let PI = Math.PI; //繪制 ctx.beginPath(); //left ctx.moveTo(x, y); //top ctx.arc(x + (w + 5) / 2, y, r, -PI, 0, true); ctx.lineTo(x + w + 5, y); //right ctx.arc(x + w + 5, y + w / 2, r, 1.5 * PI, 0.5 * PI, false); ctx.lineTo(x + w + 5, y + w); //bottom ctx.arc(x + (w + 5) / 2, y + w, r, 0, PI, false); ctx.lineTo(x, y + w); ctx.arc(x, y + w / 2, r, 0.5 * PI, 1.5 * PI, true); ctx.lineTo(x, y); //修飾,沒有會看不出效果 ctx.lineWidth = 1; ctx.fillStyle = "rgba(255, 255, 255, 0.5)"; ctx.strokeStyle = "rgba(255, 255, 255, 0.5)"; ctx.stroke(); ctx[type](); ctx.globalCompositeOperation = "xor"; }
解釋下:
參數是傳入canvas對象
x,y軸數據
剪切還是填充的canvas函數(fill,clip)
繪制難點:(很重要,不然你沒法理解它怎么繪制的)
繪制主要是需要理解這里的繪制是根據你設置一個起始點坐標,然后你繪制第二次的時候線就會連接到第二個點,依次連接最后回到原點就形成一個完整的圖形。
圓形的繪制:來自:https://www.w3school.com.cn/tags/canvas_arc.asp
用的是arc參數,主要是看這個圖
fill是用于填充繪制的部分,clip是裁剪出繪制的部分,利用這個就可以出現一個扣掉的圖片和一個裁剪出來的圖片。
完成之后就是我的那個函數了。大家可以直接拿去用。
3、讓元素跟隨鼠標點擊之后滑動
這里其實原理非常簡單,就是有一個注意點。
原理:
鼠標點擊之后記錄當前坐標,然后隨著( mousemove )滾動的時候修改元素的left和top值就行了。
還有一點就是鼠標快速滑動會導致丟失滑動效果,這里需要用document,不能是元素級別的監聽。
元素上面我只需要鑒定按下 mousedown
代碼:
//鼠標按下 drag(e) { console.log("鼠標按下", e); let dom = e.target; //dom元素 let slider = document.querySelector("#sliderBlock"); //滑塊dom const downCoordinate = { x: e.x, y: e.y }; //正確的滑塊數據 let checkx = Number(this.slider.mx) - Number(this.slider.bx); //x軸數據 let x = 0; const move = moveEV => { x = moveEV.x - downCoordinate.x; //y = moveEV.y - downCoordinate.y; if (x >= 251 || x <= 0) return false; dom.style.left = x + "px"; //dom.style.top = y + "px"; slider.style.left = x + "px"; }; const up = () => { document.removeEventListener("mousemove", move); document.removeEventListener("mouseup", up); dom.style.left = ""; console.log(x, checkx); let max = checkx - 5; let min = checkx - 10; //允許正負誤差1 if ((max >= x && x >= min) || x === checkx) { console.log("滑動解鎖成功"); this.puzzle = true; this.tips = "驗證成功"; setTimeout(() => { this.visible = false; }, 500); } else { console.log("拼圖位置不正確"); this.tips = "驗證失敗,請重試"; this.puzzle = false; this.canvasInit(); } }; document.addEventListener("mousemove", move); document.addEventListener("mouseup", up); }
4、總結
核心點比較多,寫過之后發現不難,關鍵在于去寫
個人該頁面git地址:https://github.com/ht-sauce/dream
該頁面處于項目的
路由訪問為:http://localhost:8080/consumer
5、完整的頁面代碼
<template> <div id="login"> <el-form class="loginFrom" :model="logindata" :rules="rules" ref="ruleForm"> <el-form-item class="login-item"> <h2 class="login-title">海天醬油登錄中心</h2> </el-form-item> <el-form-item prop="userName"> <el-input class="login-inputorbuttom" prefix-icon="el-icon-user" placeholder="登錄名" v-model="logindata.userName" ></el-input> </el-form-item> <el-form-item prop="password"> <el-input class="login-inputorbuttom" prefix-icon="el-icon-lock" placeholder="密碼" v-model="logindata.password" ></el-input> </el-form-item> <!--<el-form-item prop="verificationCode"> <el-input class="login-inputorbuttom" v-model="logindata.verificationCode" ></el-input> </el-form-item>--> <el-form-item class="login-item"> <el-button class="login-inputorbuttom login-bottom" type="primary" v-popover:popover @click="visible = !visible" >登 錄</el-button > </el-form-item> </el-form> <!--驗證碼彈窗--> <el-popover popper-class="slidingPictures" ref="popover" trigger="manual" v-model="visible" > <div class="sliding-pictures"> <div class="vimg"> <canvas id="sliderBlock"></canvas> <canvas id="codeImg"></canvas> </div> <div class="slider"> <div class="track" :class="{ pintuTrue: puzzle }"> {{ tips }} </div> <div class="button el-icon-s-grid" @mousedown.prevent="drag"></div> </div> <div class="operation"> <span title="關閉驗證碼" @click="visible = false" class="el-icon-circle-close" ></span> <span title="刷新驗證碼" @click="canvasInit" class="el-icon-refresh-left" ></span> </div> </div> </el-popover> </div> </template> <script> export default { name: "login", data() { return { tips: "拖動左邊滑塊完成上方拼圖", logindata: { userName: "", password: "", verificationCode: "" }, rules: {}, visible: false, //滑塊x軸數據 slider: { mx: 0, bx: 0 }, //拼圖是否正確 puzzle: false }; }, watch: { visible(e) { if (e === true) { this.canvasInit(); this.puzzle = false; } } }, beforeCreate() {}, created() {}, beforeMount() {}, mounted() {}, methods: { //拼圖驗證碼初始化 canvasInit() { //生成指定區間的隨機數 const random = (min, max) => { return Math.floor(Math.random() * (max - min + 1) + min); }; //x: 254, y: 109 let mx = random(127, 244), bx = random(10, 128), y = random(10, 99); this.slider = { mx, bx }; this.draw(mx, bx, y); }, //鼠標按下 drag(e) { console.log("鼠標按下", e); let dom = e.target; //dom元素 let slider = document.querySelector("#sliderBlock"); //滑塊dom const downCoordinate = { x: e.x, y: e.y }; //正確的滑塊數據 let checkx = Number(this.slider.mx) - Number(this.slider.bx); //x軸數據 let x = 0; const move = moveEV => { x = moveEV.x - downCoordinate.x; //y = moveEV.y - downCoordinate.y; if (x >= 251 || x <= 0) return false; dom.style.left = x + "px"; //dom.style.top = y + "px"; slider.style.left = x + "px"; }; const up = () => { document.removeEventListener("mousemove", move); document.removeEventListener("mouseup", up); dom.style.left = ""; console.log(x, checkx); let max = checkx - 5; let min = checkx - 10; //允許正負誤差1 if ((max >= x && x >= min) || x === checkx) { console.log("滑動解鎖成功"); this.puzzle = true; this.tips = "驗證成功"; setTimeout(() => { this.visible = false; }, 500); } else { console.log("拼圖位置不正確"); this.tips = "驗證失敗,請重試"; this.puzzle = false; this.canvasInit(); } }; document.addEventListener("mousemove", move); document.addEventListener("mouseup", up); }, draw(mx = 200, bx = 20, y = 50) { let mainDom = document.querySelector("#codeImg"); let bg = mainDom.getContext("2d"); let width = mainDom.width; let height = mainDom.height; let blockDom = document.querySelector("#sliderBlock"); let block = blockDom.getContext("2d"); //重新賦值,讓canvas進行重新繪制 blockDom.height = height; mainDom.height = height; let imgsrc = require("../assets/images/back.jpg"); let img = document.createElement("img"); img.style.objectFit = "scale-down"; img.src = imgsrc; img.onload = function() { bg.drawImage(img, 0, 0, width, height); block.drawImage(img, 0, 0, width, height); }; let mainxy = { x: mx, y: y, r: 9 }; let blockxy = { x: bx, y: y, r: 9 }; this.drawBlock(bg, mainxy, "fill"); this.drawBlock(block, blockxy, "clip"); }, //繪制拼圖 drawBlock(ctx, xy = { x: 254, y: 109, r: 9 }, type) { let x = xy.x, y = xy.y, r = xy.r, w = 40; let PI = Math.PI; //繪制 ctx.beginPath(); //left ctx.moveTo(x, y); //top ctx.arc(x + (w + 5) / 2, y, r, -PI, 0, true); ctx.lineTo(x + w + 5, y); //right ctx.arc(x + w + 5, y + w / 2, r, 1.5 * PI, 0.5 * PI, false); ctx.lineTo(x + w + 5, y + w); //bottom ctx.arc(x + (w + 5) / 2, y + w, r, 0, PI, false); ctx.lineTo(x, y + w); ctx.arc(x, y + w / 2, r, 0.5 * PI, 1.5 * PI, true); ctx.lineTo(x, y); //修飾,沒有會看不出效果 ctx.lineWidth = 1; ctx.fillStyle = "rgba(255, 255, 255, 0.5)"; ctx.strokeStyle = "rgba(255, 255, 255, 0.5)"; ctx.stroke(); ctx[type](); ctx.globalCompositeOperation = "xor"; } } }; </script> <style> .slidingPictures { padding: 0; width: 300px; border-radius: 2px; } </style> <style scoped lang="scss"> #login { display: flex; flex-flow: row; justify-content: flex-end; align-items: center; width: 100%; height: 100%; background-image: url("../assets/images/back.jpg"); background-size: 100% 100%; .loginFrom { width: 300px; margin-top: -10vw; margin-right: 10vw; .login-item { display: flex; justify-content: center; align-items: center; } .login-title { color: #ffffff; font-size: 16px; margin-bottom: 10px; } .login-bottom { margin-top: 15px; } .login-bottom:hover { background: rgba(28, 136, 188, 0.5); } .login-bottom:active { background: rgba(228, 199, 200, 0.5); } /deep/.login-inputorbuttom { height: 40px; width: 300px; background: rgba(57, 108, 158, 0.5); border-radius: 20px; border: #396c9e 1px solid; font-size: 14px; color: #ffffff; .el-input--small, .el-input__inner { line-height: 43px; border: none; color: #ffffff; font-size: 14px; height: 40px; border-radius: 20px; background: transparent; text-align: center; } .el-input__icon { line-height: 40px; font-size: 16px; } } } } /*該樣式最終是以彈窗插入*/ .sliding-pictures { width: 100%; .vimg { width: 100%; height: 170px; #codeImg, #sliderBlock { padding: 7px 7px 0 7px; width: inherit; height: inherit; } #codeImg { //display: none; } #sliderBlock { position: absolute; z-index: 4000; } } .slider { width: 100%; height: 65px; border-bottom: #c7c9d0 1px solid; display: flex; align-items: center; justify-content: flex-start; .track { margin-left: 7px; width: 286px; height: 38px; background: rgba(28, 136, 188, 0.5); border-radius: 25px; font-size: 14px; line-height: 38px; padding-right: 15px; padding-left: 70px; } .pintuTrue { background: #67c23a; color: #ffffff; } .button { position: absolute; width: 50px; height: 50px; line-height: 48px; background: #ffffff; box-shadow: #b9bdc8 0 0 3px; border-radius: 50%; left: 7px; text-align: center; font-size: 28px; color: #3e5d8b; &:hover { color: #2181bd; } } } .operation { width: 100%; height: 40px; > span { color: #9fa3ac; display: inline-block; width: 40px; font-size: 25px; line-height: 40px; text-align: center; &:hover { background: #e2e8f5; } } } } </style>
總結
以上所述是小編給大家介紹的Vue實現滑動拼圖驗證碼功能,希望對大家有所幫助,如果大家有任何疑問歡迎給我留言,小會及時回復大家的!
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