接触的大部分项目中,验证码一直都是后台干的事,这两天正好有一个页面需要验证码,第时间想着后台实现,但突然转念一想大部分项目貌似对安全性要求不是很高,又要求有点阻止机器人的技巧,于是就用前端写了一个验证码。并利用CSS3的transform属性里的rotate设置旋转,再随机弄点干扰线,最后为了在所有DOM节点的上边加一层opacity=0的DIV,一个前端验证码就出来了。

14129549352498

Code代码:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/**
* Created by Lee on 2014/9/16.
*/
(function(){
var randstr = function(length){
var key = {

str : [
'a','b','c','d','e','f','g','h','i','j','k','l','m',
'o','p','q','r','s','t','x','u','v','y','z','w','n',
'0','1','2','3','4','5','6','7','8','9'
],

randint : function(n,m){
var c = m-n+1;
var num = Math.random() * c + n;
return Math.floor(num);
},

randStr : function(){
var _this = this;
var leng = _this.str.length - 1;
var randkey = _this.randint(0, leng);
return _this.str[randkey];
},

create : function(len){
var _this = this;
var l = len || 10;
var str = '';

for(var i = 0 ; i<l ; i++){
str += _this.randStr();
}

return str;
}

};

length = length ? length : 10;

return key.create(length);
};

var randint = function(n,m){
var c = m-n+1;
var num = Math.random() * c + n;
return Math.floor(num);
};

var vCode = function(dom, options){
this.codeDoms = [];
this.lineDoms = [];
this.initOptions(options);
this.dom = dom;
this.init();
this.addEvent();
this.update();
this.mask();
};

vCode.prototype.init = function(){
this.dom.style.position = "relative";
this.dom.style.overflow = "hidden";
this.dom.style.cursor = "pointer";
this.dom.title = "点击更换验证码";
this.dom.style.background = this.options.bgColor;
this.w = this.dom.clientWidth;
this.h = this.dom.clientHeight;
this.uW = this.w / this.options.len;
};

vCode.prototype.mask = function(){
var dom = document.createElement("div");
dom.style.cssText = [
"width: 100%",
"height: 100%",
"left: 0",
"top: 0",
"position: absolute",
"cursor: pointer",
"z-index: 9999999"
].join(";");

dom.title = "点击更换验证码";

this.dom.appendChild(dom);
};

vCode.prototype.addEvent = function(){
var _this = this;
_this.dom.addEventListener("click", function(){
_this.update.call(_this);
});
};

vCode.prototype.initOptions = function(options){

var f = function(){
this.len = 4;
this.fontSizeMin = 20;
this.fontSizeMax = 48;
this.colors = [
"green",
"red",
"blue",
"#53da33",
"#AA0000",
"#FFBB00"
];
this.bgColor = "#FFF";
this.fonts = [
"Times New Roman",
"Georgia",
"Serif",
"sans-serif",
"arial",
"tahoma",
"Hiragino Sans GB"
];
this.lines = 8;
this.lineColors = [
"#888888",
"#FF7744",
"#888800",
"#008888"
];

this.lineHeightMin = 1;
this.lineHeightMax = 3;
this.lineWidthMin = 1;
this.lineWidthMax = 60;
};

this.options = new f();

if(typeof options === "object"){
for(i in options){
this.options[i] = options[i];
}
}
};

vCode.prototype.update = function(){
for(var i=0; i<this.codeDoms.length; i++){
this.dom.removeChild(this.codeDoms[i]);
}
for(var i=0; i<this.lineDoms.length; i++){
this.dom.removeChild(this.lineDoms[i]);
}
this.createCode();
this.draw();
};

vCode.prototype.createCode = function(){
this.code = randstr(this.options.len);
};

vCode.prototype.verify = function(code){
return this.code === code;
};

vCode.prototype.draw = function(){
this.codeDoms = [];
for(var i=0; i<this.code.length; i++){
this.codeDoms.push(this.drawCode(this.code[i], i));
}

this.drawLines();
};

vCode.prototype.drawCode = function(code, index){
var dom = document.createElement("span");

dom.style.cssText = [
"font-size:" + randint(this.options.fontSizeMin, this.options.fontSizeMax) + "px",
"color:" + this.options.colors[randint(0, this.options.colors.length - 1)],
"position: absolute",
"left:" + randint(this.uW * index, this.uW * index + this.uW - 10) + "px",
"top:" + randint(0, this.h - 30) + "px",
"transform:rotate(" + randint(-30, 30) + "deg)",
"-ms-transform:rotate(" + randint(-30, 30) + "deg)",
"-moz-transform:rotate(" + randint(-30, 30) + "deg)",
"-webkit-transform:rotate(" + randint(-30, 30) + "deg)",
"-o-transform:rotate(" + randint(-30, 30) + "deg)",
"font-family:" + this.options.fonts[randint(0, this.options.fonts.length - 1)],
"font-weight:" + randint(400, 900)
].join(";");

dom.innerHTML = code;
this.dom.appendChild(dom);

return dom;
};

vCode.prototype.drawLines = function(){
this.lineDoms = [];
for(var i=0; i<this.options.lines; i++){
var dom = document.createElement("div");

dom.style.cssText = [
"position: absolute",
"opacity: " + randint(3, 8) / 10,
"width:" + randint(this.options.lineWidthMin, this.options.lineWidthMax) + "px",
"height:" + randint(this.options.lineHeightMin, this.options.lineHeightMax) + "px",
"background: " + this.options.lineColors[randint(0, this.options.lineColors.length - 1)],
"left:" + randint(0, this.w - 20) + "px",
"top:" + randint(0, this.h) + "px",
"transform:rotate(" + randint(-30, 30) + "deg)",
"-ms-transform:rotate(" + randint(-30, 30) + "deg)",
"-moz-transform:rotate(" + randint(-30, 30) + "deg)",
"-webkit-transform:rotate(" + randint(-30, 30) + "deg)",
"-o-transform:rotate(" + randint(-30, 30) + "deg)",
"font-family:" + this.options.fonts[randint(0, this.options.fonts.length - 1)],
"font-weight:" + randint(400, 900)
].join(";");
this.dom.appendChild(dom);

this.lineDoms.push(dom);
}
};

this.vCode = vCode;

}).call(this);

用法:

1
2
3
4
5
6
//container 为 验证码的DOM节点
var code = new vCode(container);

// 验证是否正确
// inputCode为用户输入的验证码
code.verify(inputCode); // return true or false

查看演示

点击下载