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利用canvas绘制带干扰线的验证码

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! DOCTYPE html html lang = "en" head meta charset = "UTF-8" meta name = "viewport" content = "width=device-width, initial-scale=1.0" meta http-equiv = "X-UA-Compatible" content = "ie=edge" title Document / title / head body div id = "vCodeI
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<!DOCTYPE html> <html lang="en">
<head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> </head>
<body> <div id="vCodeImg" style="width: 100px"></div> </body> <script> (function(window, document) { function GVerify(options) { //创建一个图形验证码对象,接收options对象为参数 this.options = { //默认options参数值 id: "", //容器Id canvasId: "verifyCanvas", //canvas的ID width: "100", //默认canvas宽度 height: "30", //默认canvas高度 type: "blend", //图形验证码默认类型blend:数字字母混合类型、number:纯数字、letter:纯字母 code: "" }
if (Object.prototype.toString.call(options) == "[object Object]") { //判断传入参数类型 for (var i in options) { //根据传入的参数,修改默认参数值 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 = { /**版本号**/ 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 = "您的浏览器版本不支持canvas"; con.appendChild(canvas); var parent = this; canvas.onclick = function() { parent.refresh(); } },
/**生成验证码**/ 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") { //判断验证码类型 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 <= 4; i++) { var txt = txtArr[randomNum(0, txtArr.length)]; this.options.code += txt; ctx.font = randomNum(this.options.height / 2, this.options.height) + ‘px SimHei‘; //随机生成字体大小 ctx.fillStyle = randomColor(50, 160); //随机生成字体颜色 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 / 5 * i; var y = this.options.height / 2; var deg = randomNum(-30, 30); /**设置旋转角度和坐标原点**/ ctx.translate(x, y); ctx.rotate(deg * Math.PI / 180); ctx.fillText(txt, 0, 0); /**恢复旋转角度和坐标原点**/ ctx.rotate(-deg * Math.PI / 180); ctx.translate(-x, -y); } /**绘制干扰线**/ 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(); } /**绘制干扰点**/ 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(); } },
/**验证验证码**/ validate: function(code) { var code = code.toLowerCase(); var v_code = this.options.code.toLowerCase(); console.log(v_code); if (code == v_code) { return true; } else { this.refresh(); return false; } } } /**生成字母数组**/ 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(","); } /**生成一个随机数**/ function randomNum(min, max) { return Math.floor(Math.random() * (max - min) + min); } /**生成一个随机色**/ 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);
// 调用GVerifty var verifyCode = new GVerify("vCodeImg"); </script>
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