Display data from database in TextBox using SqlDataReader in ASP.Net

You have to do it in this way:

HTML:

<asp:TextBox ID="txtId" runat="server" />
<asp:TextBox ID="txtName" runat="server" />
<asp:TextBox ID="txtCity" runat="server" />

C#

    protected void Page_Load(object sender, EventArgs e)
    {
        this.GetData();
    }

    private void GetData()
    {
        string constr = ConfigurationManager.ConnectionStrings("ConString2").ConnectionString;
        using (SqlConnection _cn = new SqlConnection(constr))
        {
            SqlCommand command = new SqlCommand("SELECT * FROM Person Where Name = @Name", _cn);
            // this way you have to add Parameters
            command.Parameters.AddWithValue("@Name", "Azim");

            _cn.Open();
            SqlDataReader reader = command.ExecuteReader();
            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    // where 0 is column index
                    txtId.Text = reader.GetValue(0);
                    txtName.Text = reader.GetValue(1);
                    txtCity.Text = reader.GetValue(2);
                }
            }
            else
                Console.WriteLine("No rows found.");
            reader.Close();
        }
    }

VB:

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        Me.GetData()
    End Sub

    Private Sub GetData()
        Dim constr As String = ConfigurationManager.ConnectionStrings("ConString2").ConnectionString
        Using _cn As New SqlConnection(constr)
            Dim command As New SqlCommand("SELECT * FROM Person Where Name = @Name", _cn)
            'this way you have to add Parameters
            command.Parameters.AddWithValue("@Name", "Azim")

            _cn.Open()
            Dim reader As SqlDataReader = command.ExecuteReader()
            If reader.HasRows Then
                While reader.Read()
                    'where 0 is column index
                    txtId.Text = reader.GetValue(0)
                    txtName.Text = reader.GetValue(1)
                    txtCity.Text = reader.GetValue(2)

                End While
            Else
                Console.WriteLine("No rows found.")
            End If
            reader.Close()
        End Using
    End Sub

You have to mention index of the column in Reader.GetValue(0)

Thank You.