1 var _IndextifyCode=IndentifyCode.Instance.CreateIndentifyCode(4);
2
3 IndentifyCode.Instance.CreateImage(_IndextifyCode,"image名称",100,35);//100,35大小
4
5 public class IndentifyCode
6 {
7 private static IndentifyCode instance = null;
8 public static IndentifyCode Instance
9 {
10 get
11 {
12 return instance ?? (instance = new IndentifyCode());
13 }
14 }
15
16
17
18 Random r = new Random(DateTime.Now.Millisecond);
19
20
21
22
23
24 #region 产生随机数
25 public string CreateIndentifyCode(int length)
26 {
27 //由于1,I,l,O,o,0容易混淆,则不显示
28 string allchar = "2,3,4,5,6,7,8,9,A,a,B,b,C,c,D,d,E,e,F,f," +
29 "G,g,H,h,i,J,j,K,k,L,M,m,N,n,P,p,Q,q,R,r,S,s," +
30 "T,t,U,u,V,v,W,w,X,x,Y,y,Z,z";
31 string[] allchararray = allchar.Split(',');
32 string randomcode = "";
33 int temp = -1;
34 Random rand = new Random();
35 for (int i = 0; i < length; i++)
36 {
37 if (temp != -1)
38 {
39 rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
40 }
41 int t = rand.Next(allchararray.Length);
42 if (temp == t)
43 {
44 return CreateIndentifyCode(length);
45 }
46 temp = t;
47 randomcode += allchararray[t];
48 }
49 return randomcode;
50 }
51 #endregion
52
53 }
