验证码功能一般是用于防止批量注册的&＃xff0c;不少网站为了防止用户利用机器人自动注册、登录、灌水&＃xff0c;都采用了验证码技术。所谓验证码&＃xff0c;就是将一串随机产生的数字或字母或符号或文字&＃xff0c;生成一幅图片&＃xff0c; 图片里加上一些干扰象素&＃xff08;防止OCR&＃xff09;&＃xff0c;由用户肉眼识别其中的验证码信息&＃xff0c;输入表单提交网站验证&＃xff0c;验证成功后才能使用某项功能。
常见的验证码有如下几种&＃xff1a;
1、纯数字验证码&＃xff0c;一般为四位随机数字&＃xff1b;
2、数字&＃43;字母验证码&＃xff0c;一般从数字&＃xff08;0~9&＃xff09;和字母(A~Z和a~z)中随机抽出几个字符组成&＃xff1b;
3、汉字验证码&＃xff0c;相对而言&＃xff0c;这种验证码比较少见一点&＃xff0c;实现起来也相对复杂一些&＃xff0c;但在不少网站中还是可以看到的&＃xff1b;
一、纯数字验证码的实现
&＃xff08;1&＃xff09;使用随机数方式&＃xff0c;代码如下&＃xff1a;
View Code 1 view plaincopy to clipboardprint?
2 private String GetRandomint(int codeCount)
3 {
4 Random random &＃61; new Random();
5 string min &＃61; "";
6 string max &＃61; "";
7 for (int i &＃61; 0; i
9 min &＃43;&＃61;"1";
10 max&＃43;&＃61;"9";
11 }
12 return (random.Next(Convert.ToInt32(min),Convert.ToInt32(max)).ToString());
13 }
14 private String GetRandomint(int codeCount)
15 {
16 Random random &＃61; new Random();
17 string min &＃61; "";
18 string max &＃61; "";
19 for (int i &＃61; 0; i
21 min &＃43;&＃61;"1";
22 max&＃43;&＃61;"9";
23 }
24 return (random.Next(Convert.ToInt32(min),Convert.ToInt32(max)).ToString());
25 }
(2)使用随机组合方式&＃xff0c;代码如下
View Code 1 view plaincopy to clipboardprint?
2 private string CreateRandomCode(int codeCount)
3 {
4 string allChar &＃61; "0,1,2,3,4,5,6,7,8,9";
5 string[] allCharArray &＃61; allChar.Split(&＃39;,&＃39;);
6 string randomCode &＃61; "";
7 int temp &＃61; -1;
8 Random rand &＃61; new Random();
9 for (int i &＃61; 0; i
11 if (temp !&＃61; -1)
12 {
13 rand &＃61; new Random(i * temp * ((int)DateTime.Now.Ticks));
14 }
15 int t &＃61; rand.Next(9);
16 if (temp &＃61;&＃61; t)
17 {
18 return CreateRandomCode(codeCount);
19 }
20 temp &＃61; t;
21 randomCode &＃43;&＃61; allCharArray[t];
22 }
23 return randomCode;
24 }
25 private string CreateRandomCode(int codeCount)
26 {
27 string allChar &＃61; "0,1,2,3,4,5,6,7,8,9";
28 string[] allCharArray &＃61; allChar.Split(&＃39;,&＃39;);
29 string randomCode &＃61; "";
30 int temp &＃61; -1;
31 Random rand &＃61; new Random();
32 for (int i &＃61; 0; i
34 if (temp !&＃61; -1)
35 {
36 rand &＃61; new Random(i * temp * ((int)DateTime.Now.Ticks));
37 }
38 int t &＃61; rand.Next(9);
39 if (temp &＃61;&＃61; t)
40 {
41 return CreateRandomCode(codeCount);
42 }
43 temp &＃61; t;
44 randomCode &＃43;&＃61; allCharArray[t];
45 }
46 return randomCode;
47 }
2、数字&＃43;字母验证码的实现
View Code 1 view plaincopy to clipboardprint?
2 private string CreateRandomCode(int codeCount)
3 {
4 string allChar &＃61; "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,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";
5 string[] allCharArray &＃61; allChar.Split(&＃39;,&＃39;);
6 string randomCode &＃61; "";
7 int temp &＃61; -1;
8 Random rand &＃61; new Random();
9 for (int i &＃61; 0; i
11 if (temp !&＃61; -1)
12 {
13 rand &＃61; new Random(i * temp * ((int)DateTime.Now.Ticks));
14 }
15 int t &＃61; rand.Next(61);
16 if (temp &＃61;&＃61; t)
17 {
18 return CreateRandomCode(codeCount);
19 }
20 temp &＃61; t;
21 randomCode &＃43;&＃61; allCharArray[t];
22 }
23 return randomCode;
24 }
25 private string CreateRandomCode(int codeCount)
26 {
27 string allChar &＃61; "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,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";
28 string[] allCharArray &＃61; allChar.Split(&＃39;,&＃39;);
29 string randomCode &＃61; "";
30 int temp &＃61; -1;
31 Random rand &＃61; new Random();
32 for (int i &＃61; 0; i
34 if (temp !&＃61; -1)
35 {
36 rand &＃61; new Random(i * temp * ((int)DateTime.Now.Ticks));
37 }
38 int t &＃61; rand.Next(61);
39 if (temp &＃61;&＃61; t)
40 {
41 return CreateRandomCode(codeCount);
42 }
43 temp &＃61; t;
44 randomCode &＃43;&＃61; allCharArray[t];
45 }
46 return randomCode;
47 }
48
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