当前文件路径：MyElectCourse/Login.aspx.cs

		            
 1using System;
 2using System.Data;
 3using System.Configuration;
 4using System.Collections;
 5using System.Web;
 6using System.Web.Security;
 7using System.Web.UI;
 8using System.Web.UI.WebControls;
 9using System.Web.UI.WebControls.WebParts;
10using System.Web.UI.HtmlControls;
11using System.Data.SqlClient;
12//该源码下载自www.51aspx.com(５１ａｓｐx．ｃｏｍ)
13
14public partial class Login : System.Web.UI.Page
15...{
16    protected void Page_Load(object sender, EventArgs e)
17    ...{
18
19    }
20    protected void imgbtnLogin_Click(object sender, ImageClickEventArgs e)
21    ...{
22        //接收用户输入的参数
23        string userName = txtUserName.Text.ToString().Trim();
24        string userPwd = txtPwd.Text.ToString().Trim();
25        string userRole = rblClass.SelectedValue.Trim();
26        string selectStr = "";
27        switch (userRole)
28        ...{
29            case "0":                       //身份为教师时              
30                selectStr = "Select * from Teacher where teaID = '" + userName + "'";    
31                break;
32            case "1":                       //身份为学生时
33                selectStr = "Select * from Student where stuID = '" + userName + "'";
34                break;
35            case "2":                       //身份为管理员时
36                selectStr = "Select * from Users where adminName = '" + userName + "'";
37                break;
38        }
39        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
40        SqlCommand cmd = new SqlCommand(selectStr,conn);
41        try
42        ...{
43            conn.Open();                    //打开连接
44            SqlDataReader sdr = cmd.ExecuteReader(); //执行查询
45            if (sdr.Read())                 //如果该用户存在
46            ...{
47                if (sdr.GetString(1) == userPwd) //密码正确
48                ...{
49                    Session["userName"] = userName;
50                    Session["userRole"] = userRole;
51                    conn.Close();
52                    switch (userRole)
53                    ...{
54                        case "0":           //身份为教师时              
55                            Response.Redirect("TeacherQueryElect.aspx");
56                            break;
57                        case "1":           //身份为学生时
58                            Response.Redirect("StudentElect.aspx");
59                            break;
60                        case "2":           //身份为管理员时
61                            Response.Redirect("Main.aspx");
62                            break;
63                    }                    
64                }
65                else                        //密码错误，给出提示信息！
66                ...{
67                    lblMessage.Text = "您输入的密码错误，请检查后重新输入！";
68                }
69            }
70            else                            //用户不存在或用户名输入错误
71            ...{
72                lblMessage.Text = "该用户不存在或用户名输入错误，请检查后重新输入！";
73            }
74        }
75        catch (Exception ee)
76        ...{
77            Response.Write("<script language=javascript>alert('" + ee.Message.ToString() + "')</script>");
78        }
79        finally
80        ...{
81            conn.Close();
82        }        
83    }
84}
85