JAVASCRIPT生成图形验证码

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

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getGVerify: function(id) {
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')
}
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 = '20px SimHei'
//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 / 2),
randomNum(0, this.options.height / 2)
)
ctx.lineTo(
randomNum(0, this.options.width / 2),
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 verifyCode = code.toLowerCase()
var v_code = this.options.code.toLowerCase()
if (verifyCode == v_code) {
return true
} else {
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 + ')'
}

return new GVerify(id)
}

调用方法

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var verifyCode = new GVerify(id)

验证方法

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if (verifyCode.validate(inputCode)) {
return true
} else {
return false
}