本文实例为大家分享了js生成图形验证码的具体代码，供大家参考，具体内容如下
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<a href="/tag/buzhichi/" target="_blank" class="keywords">不支持</a>canvas";
con.appendChild(canvas);
var parent = this;
canvas.onclick = function(){
parent.refresh();
}
},/**<a href="/tag/shengcheng/" target="_blank" class="keywords">生成</a>验证码**/
refresh: function() {
this.options.code = '';
var canvas = document.getElementById(this.options.canvasId);
if(canvas.getContext) {
var ctx = canvas.getContext('2d');
}
ctx.textBaseline = "middle";
ctx.fillStyle = randomColor(180,240);
ctx.fillRect(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 = '20px SimHei';
//ctx.font = randomNum(this.options.height/2,this.options.height) + 'px SimHei'; //<a href="/tag/suiji/" target="_blank" class="keywords">随机</a><a href="/tag/shengcheng/" target="_blank" class="keywords">生成</a>字体大小
ctx.fillStyle = randomColor(50,160); //<a href="/tag/suiji/" target="_blank" class="keywords">随机</a><a href="/tag/shengcheng/" target="_blank" class="keywords">生成</a>字体颜色
/* ctx.shadowOffsetX = randomNum(-3,3);
ctx.shadowOffsetY = randomNum(-3,3);*/
ctx.shadowBlur = randomNum(-3,3);
ctx.shadowColor = "rgba(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);
/**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/2),randomNum(0,this.options.height/2));
ctx.lineTo(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),this.options.height),2 * Math.PI);
ctx.fill();
}
},/**验证验证码**/
validate: function(code){
var verifyCode = code.toLowerCase();
var v_code = this.options.code.toLowerCase();
if(verifyCode == v_code){
return true;
}else{
return false;
}
}
}
/**<a href="/tag/shengcheng/" target="_blank" class="keywords">生成</a>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(",");
}
/**<a href="/tag/shengcheng/" target="_blank" class="keywords">生成</a>一个<a href="/tag/suiji/" target="_blank" class="keywords">随机</a>数**/
function randomNum(min,max) {
return Math.floor(Math.random() * (max - min) + min);
}
/**<a href="/tag/shengcheng/" target="_blank" class="keywords">生成</a>一个<a href="/tag/suiji/" target="_blank" class="keywords">随机</a>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 + ")";
}
return new GVerify(id);
}
验证方法
