How to implement Login with Roles in ASP.Net

This Way

Login Page:

<form id="form1" runat="server">
    <div>
        <table border="0" cellpadding="0" cellspacing="0">
            <tr>
                <td>
                    User Name
                </td>
                <td>
                    <asp:TextBox ID="txtUserName" runat="server" />
                </td>
            </tr>
            <tr>
                <td>
                    Password
                </td>
                <td>
                    <asp:TextBox ID="txtPassword" runat="server" TextMode="Password" />
                </td>
            </tr>
            <tr>
                <td colspan="1">
                    <asp:Button Text="Login" runat="server" OnClick="Login" />
                </td>
            </tr>
        </table>
    </div>
    </form>

Login.aspx.cs: Code file

protected void Login(object sender, EventArgs e)
    {
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        string sqlStatment = "SELECT *  FROM [Authentication] WHERE UserName = @UserName and Password = @Password";
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand(sqlStatment, con))
            {
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    cmd.Parameters.AddWithValue("@UserName", txtUserName.Text.Trim());
                    cmd.Parameters.AddWithValue("@Password", txtPassword.Text.Trim());
                    DataSet ds = new DataSet();
                    da.Fill(ds);
                    if (ds.Tables[0].Rows.Count > 0)
                    {
                        Session["IsAdmin"] = ds.Tables[0].Rows[0]["IsAdmin"];
                        Response.Redirect("Home.aspx");
                    }

                    else
                    {
                        string message = "Wrong UserName or Password";
                        System.Text.StringBuilder sb = new System.Text.StringBuilder();
                        sb.Append("<script type = 'text/javascript'>");
                        sb.Append("window.onload=function(){");
                        sb.Append("alert('");
                        sb.Append(message);
                        sb.Append("')};");
                        sb.Append("</script>");
                        ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", sb.ToString());
                    }

                }
            }
        }
    }

Home Page : Here i am having two links admin and user. If user login then he will be able to see onlu user link:

HTML:

<form id="form1" runat="server">
    <div>
        <asp:HyperLink ID="lnkAddminOnly" runat="server" NavigateUrl="~/AdminOnly.aspx" Text="Admin" />
        <asp:HyperLink ID="lnkUser" runat="server" NavigateUrl="#" Text="User" />
    </div>
    </form>

Home.aspx.cs Code file:

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            if (Session["IsAdmin"] != null)
            {
                // check if person is admin or user
                if (Session["IsAdmin"].ToString().ToUpper() == "FALSE")
                {
                    this.lnkAddminOnly.Visible = false;
                }
            }
        }
    }

If user directly put the OnlyAddmin.aspx in Url the he will be redirected to Home.aspx

C#:

protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            if (Session["IsAdmin"] != null)
            {
                if (Session["IsAdmin"].ToString().ToUpper() == "FALSE")
                {
                    Response.Redirect("Home.aspx");
                }
            }
        }
    }

Sql: I am having a column with IsAdmin which is a bit dataType

CREATE TABLE [dbo].[Authentication](
	[UserName] [varchar](50) NULL,
	[Password] [nvarchar](50) NULL,
	[IsAdmin] [bit] NULL
) ON [PRIMARY]

GO

Please check the below code in VB.

Login.aspx: 

<form id="form1" runat="server">
    <div>
        <table border="0" cellpadding="0" cellspacing="0">
            <tr>
                <td>
                    User Name
                </td>
                <td>
                    <asp:TextBox ID="txtUserName" runat="server" />
                </td>
            </tr>
            <tr>
                <td>
                    Password
                </td>
                <td>
                    <asp:TextBox ID="txtPassword" runat="server" TextMode="Password" />
                </td>
            </tr>
            <tr>
                <td colspan="1">
                    <asp:Button ID="Button1" Text="Login" runat="server" OnClick="Login" />
                </td>
            </tr>
        </table>
    </div>
    </form>

Login.aspx.vb

Protected Sub Login(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
        Dim constr As String = ConfigurationManager.ConnectionStrings("ConString2").ConnectionString
        Dim sqlStatment As String = "SELECT *  FROM [Authentication] WHERE UserName = @UserName and Password = @Password"
        Using con As New SqlConnection(constr)
            Using cmd As New SqlCommand(sqlStatment, con)
                Using da As New SqlDataAdapter(cmd)
                    cmd.Parameters.AddWithValue("@UserName", txtUserName.Text.Trim())
                    cmd.Parameters.AddWithValue("@Password", txtPassword.Text.Trim())
                    Dim ds As New DataSet()
                    da.Fill(ds)
                    If ds.Tables(0).Rows.Count > 0 Then
                        Session("IsAdmin") = ds.Tables(0).Rows(0)("IsAdmin")
                        Response.Redirect("Home.aspx")
                    Else
 
                        Dim message As String = "Wrong UserName or Password"
                        Dim sb As New System.Text.StringBuilder()
                        sb.Append("<script type = 'text/javascript'>")
                        sb.Append("window.onload=function(){")
                        sb.Append("alert('")
                        sb.Append(message)
                        sb.Append("')};")
                        sb.Append("</script>")
                        ClientScript.RegisterClientScriptBlock(Me.[GetType](), "alert", sb.ToString())
 
                    End If
                End Using
            End Using
        End Using
    End Sub

Home.aspx:

<form id="form1" runat="server">
    <div>
        <asp:HyperLink ID="lnkAddminOnly" runat="server" NavigateUrl="~/AdminOnly.aspx" Text="Admin" />
        <asp:HyperLink ID="lnkUser" runat="server" NavigateUrl="#" Text="User" />
    </div>
    </form>

Home.aspx.vb:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        If Not Me.IsPostBack Then
            If Session("IsAdmin") IsNot Nothing Then
                ' check if person is admin or user
                If Session("IsAdmin").ToString().ToUpper() = "FALSE" Then
                    Me.lnkAddminOnly.Visible = False
                End If
            End If
        End If
    End Sub

OnlyAdmin.aspx.cs

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        If Not Me.IsPostBack Then
            If Session("IsAdmin") IsNot Nothing Then
                ' check if person is admin or user
                If Session("IsAdmin").ToString().ToUpper() = "FALSE" Then
                    Me.lnkAddminOnly.Visible = False
                End If
            End If
        End If
    End Sub

Thank You.

Refer