如何通过以下条件登录页面? [英] how to do login page by following conditions?

问题描述

有人知道吗?

在登录页面中，我有2个字段1)loginemailid 2)密码....在此


当我在没有ID的情况下都输入这两个字段时，密码不在DB中，则应显示请注册以登录"，而当我单独输入密码时，则应显示无效的用户名和密码"...... ........

Can anyone know?

in login page i have 2 fields 1)loginemailid 2)password....in this


when i enter both field by no id,password not in DB it should display "Please Register to login" and when i enter the password alone weong it should display" "Invalid username and password"..................

推荐答案

示例代码:

Sample code :

private void CheckPassword()
       {
           string emailAddress = this.txtLoginRmailId.Text;
           string password = this.txtPassword.Text;
           string errorMessage;

           bool userExist = Bll.CheckIfUserExist(emailAddress);
           if (userExist == false)
           {
               errorMessage = "Please register to login";

               Response.Write(errorMessage);
           }
           else
           {
               bool userIsValid = Bll.ValidateUserCredential(emailAddress, password);
               if (userIsValid == false)
               {
                   errorMessage = "Invalid username and password";
               }

               Response.Write(errorMessage);
           }
       }

(如果您使用登录控件..

if you are using login control..

<asp:Label ID="lblMessage" runat="server" Text="Label"></asp:Label>
<asp:Login ID="ctlLogin" runat="server" OnAuthenticate="OnAuthenticate">
<LayoutTemplate>
    <asp:TextBox ID="UserName" runat="server"></asp:TextBox>
    <asp:TextBox ID="Password"  runat="server" TextMode="Password" ></asp:TextBox>
    <asp:Button ID="Button2" ValidationGroup="ctlLogin" CommandName="Login" runat="server" Text="Button" />
</LayoutTemplate>
</asp:Login>

背后的代码...

code behind...

bool Authenticated;
    protected void OnAuthenticate(object sender, AuthenticateEventArgs e)
    {
        Authenticated = false;
        Authenticated = UserAuthenticate(ctlLogin.UserName, ctlLogin.Password);
        e.Authenticated = Authenticated;
        if (Authenticated == true)
        {
            Response.Redirect("~/home.aspx");
        }
    }
    
    private bool UserAuthenticate(string UserName, string Password)
    {
        bool passwordMatch = false;
        SqlCommand cmd = new SqlCommand("Select email,Password FROM [User] where Email=@userName", con);
        cmd.CommandType = CommandType.Text;
        //Usage of Sql parameters also helps avoid SQL Injection attacks.
        SqlParameter sqlParam = cmd.Parameters.Add("@userName", SqlDbType.VarChar, 100);
        sqlParam.Value = UserName;
        try
        {
            con.Open();
            SqlDataReader reader = cmd.ExecuteReader();
            reader.Read(); // Advance to the one and only row
            // Return output parameters from returned data stream
            if (reader.HasRows) // check that reader contain the record or not
            {
                if (reader != null)
                {
                    string dbid = reader.GetString(0);
                    string dbpass = reader.GetString(1);
                    if (dbid == UserName && dbpass == Password)
                    {
                        passwordMatch = true;
                    }
                }
            }
            else
            {
                lblMessage.Text = "You have not registered yet!";
            }
        }
        catch (Exception ex)
        {
            throw new Exception("Execption verifying password. " + ex.Message);
            //lblMessage.Text = "Login error: " + ex.Message;
        }
        finally
        {
            con.Close();
        }
        return passwordMatch;
    }

希望你能有主意.祝你好运.

hope you will get idea. good luck.

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