登陆验证码

经常要用到验证码－－

如何实现呢？记得前段时间在网络上看到一个方法，结合自己的程序写了一个。

1.控件image --连接到验证码程序

2.登陆程序

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验证码程序

1. usingSystem;
2. usingSystem.Data;
3. usingSystem.Configuration;
4. usingSystem.Web;
5. usingSystem.Web.Security;
6. usingSystem.Web.UI;
7. usingSystem.Web.UI.WebControls;
8. usingSystem.Web.UI.WebControls.WebParts;
9. usingSystem.Web.UI.HtmlControls;
10. usingSystem.Drawing;
11. usingSystem.Drawing.Drawing2D;
12. publicpartialclass_Default:System.Web.UI.Page
13. {
14. protectedvoidPage_Load(objectsender,EventArgse)
15. {
16. if(!IsPostBack)
17. {
18. Bitmapb=newBitmap(50,20);
19. Graphicsg=Graphics.FromImage(b);
20. g.Clear(Color.White);
21. try
22. {
23. stringcode="";
24. Randomr=newRandom();
25. for(inti=0;i<5;i++)
26. {
27. code+=r.Next(0,10).ToString();
28. }
29. Session["Code"]=code;
30. Fontfont=newFont("Arial",13,FontStyle.Bold);
31. System.Drawing.Drawing2D.LinearGradientBrushbrush=newLinearGradientBrush(newRectangle(10,20,30,20),Color.Red,Color.Green,12.2f);
32. g.DrawString(code,font,brush,0,0);
33. System.IO.MemoryStreamstr=newSystem.IO.MemoryStream();
34. b.Save(str,System.Drawing.Imaging.ImageFormat.Gif);
35. Response.ClearContent();
36. Response.ContentType="image/gif";
37. Response.BinaryWrite(str.ToArray());
38. }
39. catch
40. {
41. g.Dispose();
42. b.Dispose();
43. }
44. }
45. }
46. }

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登陆程序

1. usingSystem;
2. usingSystem.Data;
3. usingSystem.Configuration;
4. usingSystem.Collections;
5. usingSystem.Web;
6. usingSystem.Web.Security;
7. usingSystem.Web.UI;
8. usingSystem.Web.UI.WebControls;
9. usingSystem.Web.UI.WebControls.WebParts;
10. usingSystem.Web.UI.HtmlControls;
11. usingSystem.Data.SqlClient;
12. usingSystem.Web.Caching;
14. publicpartialclasslogin:System.Web.UI.Page
15. {
16. protectedvoidPage_Load(objectsender,EventArgse)
17. {
19. }
21. protectedvoidButton1_Click(objectsender,EventArgse)
22. {
23. txtpwd.Text="";
24. txtUserName.Text="";
25. }
26. protectedvoidButton2_Click(objectsender,EventArgse)
27. {
28. StringuserName=txtUserName.Text.ToString().Trim();
29. StringuserPwd=txtpwd.Text.ToString().Trim();
30. stringCode=TextBox1.Text.Trim();
31. //StringuserPwd=System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(this.txtpwd.Text,"md5");;
33. StringStr="";
34. Str="Selectpassword,namefromuserswherename='"+userName+"'";
36. SqlConnectionconn=newSqlConnection(PublicVar.strCon_SHATDB);
37. SqlCommandcmd=newSqlCommand(Str,conn);
39. try
40. {
41. conn.Open();
42. SqlDataReadersdr=cmd.ExecuteReader();
43. if(Code==Session["Code"].ToString())
44. {
45. if(sdr.Read())
46. {
47. if(sdr.GetString(0)==userPwd)
48. {
49. Response.Redirect("index.aspx");
50. }
51. else
52. {
53. lblmessage.Text="密码错误,请重新输入";
54. }
55. }
56. else
57. {
58. lblmessage.Text="该用户不存在或输入错误，请重新输入";
59. }
60. }
61. else
62. {
63. lblmessage.Text="验证码为空或有误!";
65. }
67. }
68. catch(Exceptionee)
69. {
70. //Response.Write("<scriptlanguage=javascript>alert('"+ee.Message.toString()+'")</script>");
71. Response.Write("<script>alert('"+ee.Message.ToString()+"')</script>");
72. }
73. finally
74. {
75. conn.Close();
76. }
77. conn.Close();
79. /*//检查用户是否已经登陆
80. stringstrUser=string.Empty;
81. stringstrCacheKey=txtUserName.Text.ToString().Trim();
83. strUser=Convert.ToString(Cache[strCacheKey]);
85. if(strUser==string.Empty)
86. {
87. TimeSpanSessTimeOut=newTimeSpan(0,0,System.Web.HttpContext.Current.Session.Timeout,0,0);
89. Cache.Insert(strCacheKey,strCacheKey,null,DateTime.MaxValue,SessTimeOut,CacheItemPriority.NotRemovable,null);
90. Session["User"]=strCacheKey;
91. this.Label1.Text=Session["User"].ToString();
92. }
93. else
94. {
95. this.Label1.Text="这个用户已经登录！";
96. }
97. */
98. }
99. }