原生js生成圖片驗證碼
本文實例為大家分享了js生成圖片驗證碼的具體代碼，供大家參考，具體內容如下
html代碼
<!DOCTYPE html><html> <head> <meta charset='UTF-8'> <title>圖形驗證碼</title> </head> <body> <div style='width: 200px;height: 50px;'></div> <input type='text' value='' placeholder='請輸入驗證碼'/><button id='my_button'>驗證</button> </body> <script src='http://m.b3g6.com/js/picCode.js'></script> <script> var verifyCode = new GVerify('v_container'); document.getElementById('my_button').onclick = function(){ var res = verifyCode.validate(document.getElementById('code_input').value); if(res){ alert('驗證正確'); }else{ alert('驗證碼錯誤'); } } </script></html>
js
!(function(window, document) { var size = 5;//設置驗證碼長度 function GVerify(options) { //創建一個圖形驗證碼對象，接收options對象為參數 this.options = { //默認options參數值 id: '', //容器Id canvasId: 'verifyCanvas', //canvas的ID width: '100', //默認canvas寬度 height: '30', //默認canvas高度 type: 'blend', //圖形驗證碼默認類型blend:數字字母混合類型、number:純數字、letter:純字母 code: '', } if(Object.prototype.toString.call(options) == '[object Object]'){//判斷傳入參數類型 for(var i in options) { //根據傳入的參數，修改默認參數值 this.options[i] = options[i]; } }else{ this.options.id = options; } this.options.numArr = '0,1,2,3,4,5,6,7,8,9'.split(','); this.options.letterArr = getAllLetter(); this._init(); this.refresh(); } GVerify.prototype = { /**版本號**/ version: ’1.0.0’, /**初始化方法**/ _init: function() { var con = document.getElementById(this.options.id); var canvas = document.createElement('canvas'); this.options.width = con.offsetWidth > 0 ? con.offsetWidth : '100'; this.options.height = con.offsetHeight > 0 ? con.offsetHeight : '30'; canvas.id = this.options.canvasId; canvas.width = this.options.width; canvas.height = this.options.height; canvas.style.cursor = 'pointer'; canvas.innerHTML = '您的瀏覽器版本不支持canvas'; con.appendChild(canvas); var parent = this; canvas.onclick = function(){ parent.refresh(); } }, /**生成驗證碼**/ refresh: function() { this.options.code = ''; var canvas = document.getElementById(this.options.canvasId); if(canvas.getContext) { var ctx = canvas.getContext(’2d’); }else{ return; } ctx.textBaseline = 'middle'; ctx.fillStyle = randomColor(180, 240); ctx.fillRect(0, 0, this.options.width, this.options.height); if(this.options.type == 'blend') { //判斷驗證碼類型 var txtArr = this.options.numArr.concat(this.options.letterArr); } else if(this.options.type == 'number') { var txtArr = this.options.numArr; } else { var txtArr = this.options.letterArr; } for(var i = 1; i <=size; i++) { var txt = txtArr[randomNum(0, txtArr.length)]; this.options.code += txt; ctx.font = randomNum(this.options.height/2, this.options.height) + ’px SimHei’; //隨機生成字體大小 ctx.fillStyle = randomColor(50, 160); //隨機生成字體顏色 ctx.shadowOffsetX = randomNum(-3, 3); ctx.shadowOffsetY = randomNum(-3, 3); ctx.shadowBlur = randomNum(-3, 3); ctx.shadowColor = 'rgba(0, 0, 0, 0.3)'; var x = this.options.width / (size+1) * i; var y = this.options.height / 2; var deg = randomNum(-30, 30); /**設置旋轉角度和坐標原點**/ ctx.translate(x, y); ctx.rotate(deg * Math.PI / 180); ctx.fillText(txt, 0, 0); /**恢復旋轉角度和坐標原點**/ ctx.rotate(-deg * Math.PI / 180); ctx.translate(-x, -y); } /**繪制干擾線**/ for(var i = 0; i < 4; i++) { ctx.strokeStyle = randomColor(40, 180); ctx.beginPath(); ctx.moveTo(randomNum(0, this.options.width), randomNum(0, this.options.height)); ctx.lineTo(randomNum(0, this.options.width), randomNum(0, this.options.height)); ctx.stroke(); } /**繪制干擾點**/ for(var i = 0; i < this.options.width/4; i++) { ctx.fillStyle = randomColor(0, 255); ctx.beginPath(); ctx.arc(randomNum(0, this.options.width), randomNum(0, this.options.height), 1, 0, 2 * Math.PI); ctx.fill(); } }, /**驗證驗證碼**/ validate: function(code){ var code = code.toLowerCase(); var v_code = this.options.code.toLowerCase(); if(code == v_code){ return true; }else{ this.refresh(); return false; } } } /**生成字母數組**/ function getAllLetter() { var letterStr = 'a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z'; return letterStr.split(','); } /**生成一個隨機數**/ function randomNum(min, max) { return Math.floor(Math.random() * (max - min) + min); } /**生成一個隨機色**/ function randomColor(min, max) { var r = randomNum(min, max); var g = randomNum(min, max); var b = randomNum(min, max); return 'rgb(' + r + ',' + g + ',' + b + ')'; } window.GVerify = GVerify;})(window, document);
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持好吧啦網。
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