/*********************************登录系统 类文件**************************************************/

using System.Text;
using System.Security.Cryptography;//MD5加密需引入的命名空间
using System.Data.SqlClient;//数据库操作需引入的命名空间

/// <summary>
/// DB 的摘要说明
/// </summary>
public class DB
{
	public DB()
	{
		//
		// TODO: 在此处添加构造函数逻辑
		//
	}

    /// <summary>
    /// 连接数据库
    /// </summary>
    /// <returns>返回SqlConnection对象</returns>
    public SqlConnection GetCon()
    {
        return new SqlConnection(ConfigurationManager.AppSettings["ConnectionString"].ToString());
    }

    /// <summary>
    /// 执行SQL语句
    /// </summary>
    ///<param name="cmdstr">SQL语句</param>
    /// <returns>返回值为int型：成功返1，失败返回0</returns>
    public int sqlEx(string cmdstr)
    {
        SqlConnection con = GetCon();//连接数据库
        con.Open();//打开连接
        SqlCommand cmd = new SqlCommand(cmdstr, con);
        try
        {
            cmd.ExecuteNonQuery();//执行SQL 语句并返回受影响的行数
            return 1;//成功返回１
        }
        catch (Exception e)
        {
            return 0;//失败返回０
        }
        finally
        {
            con.Dispose();//释放连接对象资源
        }
    }
    
    /// <summary>
    /// 执行SQL查询语句
    /// </summary>
    /// <param name="cmdstr">查询语句</param>
    /// <returns>返回DataTable数据表</returns>
    public DataTable reDt(string cmdstr)
    {
        SqlConnection con =GetCon();
        SqlDataAdapter da = new SqlDataAdapter(cmdstr, con);
        DataSet ds = new DataSet();
        da.Fill(ds);
        return (ds.Tables[0]);
    }
    /// <summary>
    /// 执行SQL查询语句
    /// </summary>
    /// <param name="str">查询语句</param>
    /// <returns>返回SqlDataReader对象dr</returns>
    public SqlDataReader reDr(string str)
    {
        SqlConnection conn = GetCon();//连接数据库
        conn.Open();//并打开了连接
        SqlCommand com = new SqlCommand(str, conn);
        SqlDataReader dr = com.ExecuteReader(CommandBehavior.CloseConnection);
        return dr;//返回SqlDataReader对象dr
    }
    /// <summary>
    /// MD5加密
    /// </summary>
    /// <param name="strPwd">被加密的字符串</param>
    /// <returns>返回加密后的字符串</returns>
    public string GetMD5(string strPwd)
    {
        string pwd = "";
        //实例化一个md5对象
        MD5 md5 = MD5.Create();
        // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择
        byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(strPwd));
        //翻转生成的MD5码        
        s.Reverse();    
        //通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
        //只取MD5码的一部分，这样恶意访问者无法知道取的是哪几位
        for (int i = 3; i < s.Length - 1; i++) 
        {
            //将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符
            //进一步对生成的MD5码做一些改造
            pwd = pwd + (s[i] < 198 ? s[i] + 28 : s[i]).ToString("X"); 
        }
        return pwd;
    }
}


/*************************************登录前台文件*****************************************/
 <table style="background-image: url(Image/登录.jpg); width: 405px; height: 265px">
            <tr>
                <td style="height: 38px">
                </td>
            </tr>
            <tr>
                <td>
        <table style="width: 353px; color: #ffffff;">
            <tr>
                <td style="width: 49px">
                    用户名：</td>
                <td style="width: 97px">
                    <asp:TextBox ID="txtUserName" runat="server" Width="98px"></asp:TextBox></td>
                <td>
                </td>
            </tr>
            <tr>
                <td style="width: 49px">
                    密 &nbsp;码：</td>
                <td style="width: 97px">
                    <asp:TextBox ID="txtPwd" runat="server" TextMode="Password" Width="98px"></asp:TextBox></td>
                <td>
                </td>
            </tr>
            <tr>
                <td style="width: 49px">
                    验证码：</td>
                <td style="width: 97px">
                    <asp:TextBox ID="txtValidateNum" runat="server" Width="98px"></asp:TextBox></td>
                <td>
                    <asp:Image ID="Image1" runat="server" Height="22px"
                        Width="58px" ImageUrl="~/ValidateNum.aspx" />请输入图片中验证码！</td>
            </tr>
            <tr>
                <td style="width: 49px">
                </td>
                <td colspan="2" align="left">
                    <asp:Button ID="btnLogin" runat="server" Text="登录" OnClick="btnLogin_Click" ForeColor="DodgerBlue" /><asp:Button ID="btnRegister"
                        runat="server" Text="注册" OnClick="btnRegister_Click" ForeColor="DodgerBlue" /></td>
            </tr>
        </table>
                </td>
            </tr>
        </table>

/**************************后台代码**********************************************/
 protected void Page_Load(object sender, EventArgs e)
    {

    }
    //注册按钮
    protected void btnRegister_Click(object sender, EventArgs e)
    {
        Response.Redirect("~/Register.aspx");//跳转到用户注册页面
    }
    //登录按钮
    protected void btnLogin_Click(object sender, EventArgs e)
    {
        //实例化公共类对象
        DB db = new DB();
        string userName = this.txtUserName.Text.Trim();
        string passWord = db.GetMD5(this.txtPwd.Text.Trim());//对密码进行加密处理
        string num = this.txtValidateNum.Text.Trim();
        if (Session["ValidateNum"].ToString() == num.ToUpper())
        {
            //获取用户信息
            SqlDataReader dr = db.reDr("select * from tb_User where UserName='" + userName + "' and PassWord='" + passWord + "'");
            dr.Read();
            if (dr.HasRows)//通过dr中是否包含行判断用户是否通过身份验证
            {
                Session["UserID"] = dr.GetValue(0);//将该用户的ID存入Session["UserID"]中
                Session["Role"] = dr.GetValue(4);//将该用户的权限存入Session["Role"]中
                Response.Redirect("~/UserManagement.aspx");//跳转到主页
            }
            else
            {
                Response.Write("<script>alert('登录失败！请返回查找原因');location='Login.aspx'</script>");
            }
            dr.Close();
        }
        else
        {
            Response.Write("<script>alert('验证码输入错误！');location='Login.aspx'</script>");
        }
    }

/****************************注册网页（前台）Register.aspx *********************************************/
 <div>
        &nbsp;</div>
        <table style="background-image: url(Image/注册.jpg); width: 501px; height: 300px">
            <tr>
                <td style="height: 57px">
                </td>
            </tr>
            <tr>
                <td style="height: 203px">
        <table style="font-size: 9pt; width: 367px; height: 136px">
            <tr>
                <td style="width: 62px">
                    用户名：</td>
                <td style="width: 114px">
                    <asp:TextBox ID="txtUserName" runat="server" Width="98px"></asp:TextBox><asp:RequiredFieldValidator
                        ID="RequiredFieldValidator1" runat="server" ControlToValidate="txtUserName" ErrorMessage="*"></asp:RequiredFieldValidator></td>
                <td style="width: 164px; color: #000000;" align="left">
                    <asp:LinkButton ID="lnkbtnCheck" runat="server" CausesValidation="False" OnClick="lnkbtnCheck_Click">检测用户名是否存在</asp:LinkButton></td>
            </tr>
            <tr style="color: #000000; text-decoration: underline">
                <td style="width: 62px; height: 28px">
                    密码：</td>
                <td style="width: 114px; height: 28px">
                    <asp:TextBox ID="txtPwd" runat="server" TextMode="Password" Width="98px"></asp:TextBox><asp:RequiredFieldValidator
                        ID="RequiredFieldValidator2" runat="server" ControlToValidate="txtPwd" ErrorMessage="*"></asp:RequiredFieldValidator></td>
                <td style="width: 164px; height: 28px" align="left">
                </td>
            </tr>
            <tr>
                <td style="width: 62px">
                    确认密码：</td>
                <td style="width: 114px">
                    <asp:TextBox ID="txtRepwd" runat="server" TextMode="Password" Width="98px"></asp:TextBox><asp:RequiredFieldValidator
                        ID="RequiredFieldValidator3" runat="server" ControlToValidate="txtRepwd" ErrorMessage="*"></asp:RequiredFieldValidator></td>
                <td style="width: 164px" align="left">
                    <asp:CompareValidator ID="CompareValidator1" runat="server" ControlToCompare="txtPwd"
                        ControlToValidate="txtRepwd" ErrorMessage="确认密码不符!"></asp:CompareValidator></td>
            </tr>
            <tr>
                <td style="width: 62px; height: 26px">
                    Email：</td>
                <td style="width: 114px; height: 26px">
                    <asp:TextBox ID="txtEmail" runat="server" Width="98px"></asp:TextBox><asp:RequiredFieldValidator
                        ID="RequiredFieldValidator4" runat="server" ControlToValidate="txtEmail" ErrorMessage="*"></asp:RequiredFieldValidator></td>
                <td style="width: 164px; height: 26px" align="left">
                    <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ControlToValidate="txtEmail"
                        ErrorMessage="Email格式不正确！" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"></asp:RegularExpressionValidator></td>
            </tr>
            <tr>
                <td style="width: 62px; height: 15px">
                </td>
                <td colspan="2" style="color: red; height: 15px">
                    以上内容为必填项，请正确填写，否则无法完成注册！</td>
            </tr>
            <tr>
                <td style="width: 62px; height: 26px">
                </td>
                <td style="width: 114px; height: 26px">
                    <asp:Button ID="btnOk" runat="server" OnClick="btnOk_Click" Text="注册" />
                    <asp:Button ID="btnBack" runat="server" CausesValidation="False" OnClick="btnBack_Click"
                        Text="返回" /></td>
                <td style="width: 164px; height: 26px">
                </td>
            </tr>
        </table>
                </td>
            </tr>
            <tr>
                <td>
                </td>
            </tr>
        </table>



/****************************注册网页（后台）Register.aspx.cs*********************************************/
int reValue;//用于保存返回值。返回值为-1（用户名存在），0（失败），1（成功），2（用户名不存在）
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    //注册新用户
    protected void btnOk_Click(object sender, EventArgs e)
    {
        reValue = CheckName();
        if (reValue == -1)
        {
            Response.Write("<script>alert('用户名存在！');</script>");
        }
        else
        {
            DB db = new DB();
            string UserName = this.txtUserName.Text;
            string PassWord = db.GetMD5 (this.txtPwd.Text.ToString ());//MD5加密
            string Email = this.txtEmail.Text;
            
            string cmdstr = "insert into tb_User(UserName,PassWord,Email) values('" + UserName + "','" + PassWord + "','" + Email + "')";
            try
            {
                reValue = db.sqlEx(cmdstr);
                if (reValue == 1)
                {
                    Response.Write("<script>alert('注册成功！');</script>");
                    Clear();//清空文本框
                }
                else if (reValue == 0)
                {
                    Response.Write("<script>alert('注册失败！');</script>");
                }
            }
            catch (Exception ee)
            {
                Response.Write("<script>alert('注册失败！');</script>");
            }
        }
    }
    //检测用户名是否存在
    protected void lnkbtnCheck_Click(object sender, EventArgs e)
    {
        //查找用户名是否存在,已经存在返回-1，不存在返回2
        reValue = CheckName();
        if (reValue == -1)
        {
            Response.Write("<script>alert('用户名存在！');</script>");
            this.txtUserName.Focus();
        }
        else if (reValue == 2)
        {
            Response.Write("<script>alert('恭喜您！该用户名尚未注册！');</script>");
            this.txtUserName.Focus();
        }
    }
    //验证用户名是否存在
    public int CheckName()
    {
        //实例化公共类对象
        DB db = new DB();
        string str = "select count(*) from tb_User where UserName='" + this.txtUserName.Text + "'";
        try
        {
            DataTable dt =db.reDt(str);
            if (dt.Rows[0][0].ToString() != "0")
            {
                return -1;//该用户名已经存在
            }
            else
            {
                return 2;//该用户名尚未注册
            }
        }
        catch (Exception ee)
        {
            return 0;
        }
    }
    //清空文本框
    public void Clear()
    {
        this.txtUserName.Text = "";
        this.txtPwd.Text = "";
        this.txtRepwd.Text = "";
        this.txtEmail.Text = "";
    }
    //返回登录页
    protected void btnBack_Click(object sender, EventArgs e)
    {
        Response.Redirect("~/Login.aspx");
    }

/*************************************用户管理前台******************************/
<div style="font-size: 9pt; text-align: center;">
        <table style="font-size: 9pt; width: 501px; height: 54px; border-right: #0066cc 1px double;border-left: #0066cc 1px double; text-align: center; border-top: 1px double; border-bottom: 1px double;" cellpadding="0" cellspacing="0">
            <tr>
                <td style="background-image: url(Image/用户管理Head.jpg); height: 60px" align="right" valign="bottom">
                    <asp:LinkButton ID="lnkbtnExit" runat="server" OnClick="lnkbtnExit_Click" ForeColor="White">退出</asp:LinkButton></td>
            </tr>
            <tr>
                <td style="height: 253px">
                
                    <asp:DataList ID="DataList1" runat="server" CellPadding="4" ForeColor="#333333" OnEditCommand="DataList1_EditCommand" OnCancelCommand="DataList1_CancelCommand" OnUpdateCommand="DataList1_UpdateCommand" OnDeleteCommand="DataList1_DeleteCommand" OnItemCommand="DataList1_ItemCommand" OnItemDataBound="DataList1_ItemDataBound" Font-Size="9pt">
                        <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                        <SelectedItemStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
                       <ItemTemplate>
                            <table style="width: 470px; font-size: 9pt;">
                                <tr>
                                    <td style="width: 47px">
                                        <asp:LinkButton ID="lnkbtnUserName" runat="server" CommandName="select" Text='<%# DataBinder.Eval(Container.DataItem,"UserName") %>'></asp:LinkButton></td>
                                    <td style="width: 74px">
                                        <asp:Label ID="Label2" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"Email")%>'></asp:Label></td>
                                    <td style="width: 81px">
                                        <asp:CheckBox ID="chkRole" Checked ='<%#DataBinder.Eval(Container.DataItem,"Role")%>' runat="server" Enabled="False" /></td>
                                    <td style="width: 90px">
                                        <asp:Button ID="btnEdit" runat="server" CommandName="edit" Text="编辑" />
                                        <asp:Button ID="btnDelete" runat="server" CommandName="delete" Text="删除" CommandArgument='<%# DataBinder.Eval(Container.DataItem,"UserID") %>' OnLoad="btnDelete_Load" /></td>
                                    <td style="width: 86px">
                                        <asp:Button ID="btnSetRole" runat="server" CommandName="setRole" Text='<%# (bool) DataBinder.Eval(Container.DataItem,"Role")==true?"取消管理员权限":"设为管理员权限" %>' CommandArgument = '<%# DataBinder.Eval(Container.DataItem,"UserID") %>'/></td>
                                </tr>
                            </table>
                        </ItemTemplate>
                        <EditItemTemplate>
                            <table style="width: 297px; height: 59px; font-size: 9pt;">
                                <tr>
                                    <td style="width: 75px; height: 19px;">
                                        用户名：</td>
                                    <td style="width: 131px; height: 19px;">
                                        <asp:Label ID="lblUserName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem,"UserName") %>'></asp:Label></td>
                                    <td style="width: 95px; height: 19px;">
                                    </td>
                                </tr>
                                <tr>
                                    <td style="width: 75px">
                                        旧密码：</td>
                                    <td style="width: 131px">
                                        <asp:TextBox ID="txtOldpwd" runat="server" TextMode="Password" Width="98px"></asp:TextBox>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="txtOldpwd"
                                            ErrorMessage="*"></asp:RequiredFieldValidator></td>
                                    <td style="width: 95px">
                                    </td>
                                </tr>
                                <tr>
                                    <td style="width: 75px">
                                        新密码：</td>
                                    <td style="width: 131px">
                                        <asp:TextBox ID="txtNewpwd" runat="server" TextMode="Password" Width="98px"></asp:TextBox>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="txtNewpwd"
                                            ErrorMessage="*"></asp:RequiredFieldValidator></td>
                                    <td style="width: 95px">
                                        </td>
                                </tr>
                                <tr>
                                    <td style="width: 75px">
                                        确认密码：</td>
                                    <td style="width: 131px">
                                        <asp:TextBox ID="txtRepwd" runat="server" TextMode="Password" Width="98px"></asp:TextBox>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="txtRepwd"
                                            ErrorMessage="*"></asp:RequiredFieldValidator></td>
                                    <td style="width: 95px">
                                        <asp:CompareValidator ID="CompareValidator1" runat="server" ControlToCompare="txtNewpwd"
                                            ControlToValidate="txtRepwd" ErrorMessage="与密码不符！" Width="73px"></asp:CompareValidator></td>
                                </tr>
                                <tr>
                                    <td style="width: 75px">
                                    </td>
                                    <td style="width: 131px">
                                        <asp:Button ID="btnUpdate" runat="server" CommandName="update" CommandArgument = '<%#DataBinder.Eval(Container.DataItem,"PassWord")%>' Text="修改密码" />
                                        <asp:Button ID="btnCancel" runat="server" CommandName="cancel" Text="取消" CausesValidation="False" /></td>
                                    <td style="width: 95px">
                                    </td>
                                </tr>
                            </table>
                        </EditItemTemplate>
                        <AlternatingItemStyle BackColor="White" ForeColor="#284775" />
                        <ItemStyle BackColor="#EBF6FD" ForeColor="#333333" />
                        <HeaderTemplate>
                            <table style="width: 471px; font-size: 9pt;">
                                <tr>
                                    <td style="width: 47px">
                                        用户名</td>
                                    <td style="width: 77px">
                                        电子邮件</td>
                                    <td style="width: 81px">
                                        是否为管理员</td>
                                    <td style="width: 89px;">
                                        操作</td>
                                    <td style="width: 89px">
                                        管理员设置</td>
                                </tr>
                            </table>
                        </HeaderTemplate>
                        <HeaderStyle BackColor="#0973DC" Font-Bold="True" ForeColor="White" />
                        <SelectedItemTemplate>
                            <table style="width: 297px; height: 59px; font-size: 9pt;">
                                <tr>
                                    <td style="width: 58px; height: 19px;">
                                        用户名：</td>
                                    <td style="width: 131px; height: 19px;">
                                        <asp:TextBox ID="txtUserName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem,"UserName") %>'
                                            Width="98px"></asp:TextBox>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ControlToValidate="txtUserName"
                                            ErrorMessage="*"></asp:RequiredFieldValidator></td>
                                </tr>
                                <tr>
                                    <td style="width: 58px">
                                        Email：</td>
                                    <td style="width: 131px">
                                        <asp:TextBox ID="txtEmail" runat="server" Text='<%# DataBinder.Eval(Container.DataItem,"Email") %>'
                                            Width="98px"></asp:TextBox>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="txtEmail"
                                            ErrorMessage="*"></asp:RequiredFieldValidator></td>
                                </tr>
                                <tr>
                                    <td style="width: 58px">
                                    </td>
                                    <td style="width: 131px">
                                        <asp:Button ID="btnUpdateName" runat="server" CommandName="updateName" CommandArgument = '<%# DataBinder.Eval(Container.DataItem,"UserID") %>' Text="修改用户信息" Width="84px" />
                                        <asp:Button ID="btnCancel" runat="server" CommandName="cancel" Text="取消" CausesValidation="False" /></td>
                                </tr>
                            </table>
                        </SelectedItemTemplate>
                    </asp:DataList></td>
            </tr>
            <tr>
                <td style="height: 30px; background-image: url(Image/用户管理Bottom.jpg);">
                </td>
            </tr>
        </table>
    
    </div>
/********************************用户管理后台*UserManagement.aspx.cs****************************/
public static string selVal;//设置查询条件
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            if (Convert.ToBoolean (Session["Role"]))
                selVal = "";
            else
            {
                selVal = "where UserID="+Session["UserID"].ToString();
            }
            DataListBind();
        }
    }

    //用于绑定DataList控件
    public void DataListBind()
    {
        //实例化公共类的对象
        DB db = new DB();
        //定义SQL语句
        string sqlstr = "select * from tb_User "+selVal ;
        //实例化数据集DataTable用于存储查询结果
        DataTable dt =db.reDt(sqlstr);
        //绑定DataList控件
        DataList1.DataSource = dt;//设置数据源，用于填充控件中的项的值列表
        DataList1.DataBind();//将控件及其所有子控件绑定到指定的数据源
    }

    //显示EditTemplate模板
    protected void DataList1_EditCommand(object source, DataListCommandEventArgs e)
    {
        //设置DataList1控件的编辑项的索引为选择的当前索引
        DataList1.EditItemIndex = e.Item.ItemIndex;
        //数据绑定
        DataListBind();
    }

    //取消显示EditTemplate模板
    protected void DataList1_CancelCommand(object source, DataListCommandEventArgs e)
    {
        //设置DataList1控件的编辑项的索引为－1，即取消编辑
        DataList1.EditItemIndex = -1;
        //数据绑定
        DataListBind();
    }

    //修改用户密码
    protected void DataList1_UpdateCommand(object source, DataListCommandEventArgs e)
    {
        //实例化公共类的对象
        DB db = new DB();
        //取得文本框中输入的内容
        string userName = ((Label)e.Item.FindControl("lblUserName")).Text;
        string oldpassWord = ((TextBox)e.Item.FindControl("txtOldpwd")).Text;
        string newpassWord = ((TextBox)e.Item.FindControl("txtNewpwd")).Text;
        if (db.GetMD5(oldpassWord) == e.CommandArgument.ToString())
        {
            string sqlStr = "update tb_User set PassWord='" + db.GetMD5(newpassWord) + "'where UserName='" + userName + "'";
            //更新数据库，变量reValue用于保存执行Sql语句的返回值，成功为１，失败为０
            int reValue = db.sqlEx(sqlStr);
            
            if (reValue == 0)
                Response.Write("<script>alert('密码修改失败！');</script>");
            else
                Response.Write("<script>alert('您的密码已经成功修改！');</script>");
            //取消编辑状态
            DataList1.EditItemIndex = -1;
            DataListBind();
        }
        else
        {
            Response.Write("<script>alert('您输入的旧密码不正确。您的密码没有被更改。');</script>");
        }
    }

    protected void DataList1_ItemCommand(object source, DataListCommandEventArgs e)
    {
        //实例化公共类的对象
        DB db = new DB();
        //显示selectTemplate模板
        if (e.CommandName == "select")
        {
            //设置选中行的索引为当前选择行的索引
            DataList1.SelectedIndex = e.Item.ItemIndex;
            //数据绑定
            DataListBind();
        }
        //对selectTemplate模板中的用户名及Email信息进行更改
        if (e.CommandName == "updateName")
        {
            string userName = ((TextBox)e.Item.FindControl("txtUserName")).Text;
            string email = ((TextBox)e.Item.FindControl("txtEmail")).Text;
            string userID = e.CommandArgument.ToString ();
            string sqlStr = "update tb_User set UserName='" + userName + "',Email='"+email+"' where UserID="+ userID;
            //更新数据库，变量reValue用于保存执行Sql语句的返回值，成功为１，失败为０
            int reValue = db.sqlEx(sqlStr);
            if (reValue == 0)
                Response.Write("<script>alert('用户信息修改失败！');</script>");

            //取消选择状态
            DataList1.SelectedIndex = -1;
            DataListBind();
        }
        //取消显示selectTemplate模板
        if (e.CommandName == "cancel")
        {
            //设置选中行的索引为-1,取消该数据项的选择
            DataList1.SelectedIndex = -1;
            //数据绑定
            DataListBind();
        }
        //设置用户的管理员权限
        if (e.CommandName == "setRole")
        {
            string userID = e.CommandArgument.ToString();
            string roleText = ((Button)e.Item.FindControl("btnSetRole")).Text;
            bool role = (roleText == "取消管理员权限" ? false : true);
            string sqlStr = "update tb_User set Role='" + role + "'where UserID=" + userID;
            //更新数据库，变量reValue用于保存执行Sql语句的返回值，成功为１，失败为０
            int reValue = db.sqlEx(sqlStr);

            if (reValue == 0)
                Response.Write("<script>alert('管理员设置失败！');</script>");
            //重新绑定
            DataListBind();
        }
    }
    //删除该条记录
    protected void DataList1_DeleteCommand(object source, DataListCommandEventArgs e)
    {
        //实例化公共类的对象
        DB db = new DB();
        string userID = e.CommandArgument.ToString();
        string sqlStr = "delete from tb_User where UserID=" + userID;
        //更新数据库，变量reValue用于保存执行Sql语句的返回值，成功为１，失败为０
        int reValue = db.sqlEx(sqlStr);
        if (reValue == 0)
            Response.Write("<script>alert('删除失败！');</script>");
        //重新绑定
        DataListBind();
    }
    //删除记录前显示提示信息
    protected void btnDelete_Load(object sender, EventArgs e)
    {
        ((Button)sender).Attributes["onclick"] = "javascript:return confirm('你确认要删除该条记录吗？')";
    }
    //退出
    protected void lnkbtnExit_Click(object sender, EventArgs e)
    {
        //清空Session中的内容,并停止Session
        Session["ValidateNum"] = null;
        Session["Role"] = null;
        Session["UserID"] = null;
        Session.Clear();
        Session.Abandon();
        //跳转到登录页
        Response.Redirect("~/Login.aspx");

    }
    //根据用户权限判断该用户是否可以设置管理员
    protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)
    {
        if (!Convert.ToBoolean(Session["Role"]))
        {
            switch (e.Item.ItemType)
            {
                case ListItemType.Item:
                    ((Button)e.Item.FindControl("btnSetRole")).Enabled = false;
                    break;
                case ListItemType .AlternatingItem :
                    ((Button)e.Item.FindControl("btnSetRole")).Enabled = false;
                    break;
            }
        }
    }

/***************************************ValidateNum.aspx 验证码（后台，前台无代码）*****************************************************/
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;//引入命名空间

public partial class ValidateNum : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string validateNum = CreateRandomNum(4);//成生4位随机字符串
            CreateImage(validateNum);//将生成的随机字符串绘成图片
            Session["ValidateNum"] = validateNum;//保存验证码
        }
    }
    //生成随机字符串
    private string CreateRandomNum(int NumCount)
    {
        string allChar = "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";
        string[] allCharArray = allChar.Split(',');//拆分成数组
        string randomNum = "";
        int temp = -1;//记录上次随机数的数值，尽量避免产生几个相同的随机数

        Random rand = new Random();
        for (int i = 0; i < NumCount; i++)
        {
            if (temp != -1)
            {
                rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
            }
            int t = rand.Next(35);
            if (temp == t)
            {
                return CreateRandomNum(NumCount);
            }
            temp = t;
            randomNum += allCharArray[t];
        }
        return randomNum;
    }
    //生成图片
    private void CreateImage(string validateNum)
    {
        if (validateNum == null || validateNum.Trim() == String.Empty)
            return;
        //生成Bitmap图像
        System.Drawing.Bitmap image = new System.Drawing.Bitmap(validateNum.Length * 12 + 10, 22);
        Graphics g = Graphics.FromImage(image);

        try
        {
            //生成随机生成器 
            Random random = new Random();

            //清空图片背景色 
            g.Clear(Color.White);

            //画图片的背景噪音线 
            for (int i = 0; i < 25; i++)
            {
                int x1 = random.Next(image.Width);
                int x2 = random.Next(image.Width);
                int y1 = random.Next(image.Height);
                int y2 = random.Next(image.Height);

                g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
            }

            Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
            System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
            g.DrawString(validateNum, font, brush, 2, 2);

            //画图片的前景噪音点 
            for (int i = 0; i < 100; i++)
            {
                int x = random.Next(image.Width);
                int y = random.Next(image.Height);

                image.SetPixel(x, y, Color.FromArgb(random.Next()));
            }

            //画图片的边框线 
            g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            //将图像保存到指定的流
            image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
            Response.ClearContent();
            Response.ContentType = "image/Gif";
            Response.BinaryWrite(ms.ToArray());
        }
        finally
        {
            g.Dispose();
            image.Dispose();
        }
    }
}