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>
js
!(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);
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持免费资源网。
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