原生js生成图片验证码_JavaScript

本文实例为大家分享了js生成图片验证码的具体代码，供大家参考，具体内容如下

html代码

				?

									<!DOCTYPE html>

									<html>

									 <head>

									  <meta charset="UTF-8">

									  <title>图形验证码</title>

									 </head>

									 <body>

									  <div id="v_container" style="width: 200px;height: 50px;"></div>

									  <input type="text" id="code_input" value="" placeholder="请输入验证码"/><button id="my_button">验证</button>

									 </body>

									 <script src="../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("验证正确");

									   }else{

									    alert("验证码错误");

									   }

									  }

									 </script>

									</html>

				?

									!(function(window, document) {

									 var size = 5;//设置验证码长度

									 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 <=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'; //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 / (size+1) * 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();

									   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);