How to Bind/Fill/Populate DropDownList from DataTable in Asp.Net using C# and VB.Net

 

In this article I will explain how to bind/fill/populate dropdownlist from a datatable in Asp.Net using C# and VB.Net.

You need to add html dropdown component in aspx page to bind/fill/populate the dropdown.

HTML

<asp:DropDownList runat="server" ID="ddlCountry"></asp:DropDownList>

You need to add a namespace in code behind file.

C#

using System.Data;

VB.Net

Imports System.Data

Now, need to initialize datatable before page load event or you can initialize datatable as per your requirement.

C#

 DataTable dt = new DataTable();

VB.Net

Dim dt As DataTable = New DataTable()

Now, I will add data to the datatable on page load event or you can add data to the datatable at any event as per your requirement.

C#

protected void Page_Load(object sender, EventArgs e)
{
     if (!this.IsPostBack)
         {
                dt.Clear();
                dt.Columns.Add("Id");
                dt.Columns.Add("Country");
                DataRow dr = dt.NewRow();
                dr["Id"] = 1;
                dr["Country"] = "India";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 2;
                dr["Country"] = "Australia";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 3;
                dr["Country"] = "Srilanka";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 4;
                dr["Country"] = "Bangladesh";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 5;
                dr["Country"] = "New Zealand";
                dt.Rows.Add(dr);
                BindDropdownList();
      }
 }

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If Not Me.IsPostBack Then
        dt.Clear()
        dt.Columns.Add("Id")
        dt.Columns.Add("Country")
        Dim dr As DataRow = dt.NewRow()
        dr("Id") = 1
        dr("Country") = "India"
        dt.Rows.Add(dr)
        dr = dt.NewRow()
        dr("Id") = 2
        dr("Country") = "Australia"
        dt.Rows.Add(dr)
        dr = dt.NewRow()
        dr("Id") = 3
        dr("Country") = "Srilanka"
        dt.Rows.Add(dr)
        dr = dt.NewRow()
        dr("Id") = 4
        dr("Country") = "Bangladesh"
        dt.Rows.Add(dr)
        dr = dt.NewRow()
        dr("Id") = 5
        dr("Country") = "New Zealand"
        dt.Rows.Add(dr)
        BindDropdownList()
    End If
End Sub

Now, I will create the function BindDropdownList().

C#

public void BindDropdownList()
{
    if (dt.Rows.Count > 0)
    {
        ddlCountry.DataSource = dt;
        ddlCountry.DataTextField = "Country";
        ddlCountry.DataValueField = "Id";
        ddlCountry.DataBind();
    }
    ddlCountry.Items.Insert(0, new ListItem("--Select Country--", "0"));
}

VB.Net

Public Sub BindDropdownList()
    If dt.Rows.Count > 0 Then
        ddlCountry.DataSource = dt
        ddlCountry.DataTextField = "Country"
        ddlCountry.DataValueField = "Id"
        ddlCountry.DataBind()
    End If
    ddlCountry.Items.Insert(0, New ListItem("--Select Country--", "0"))
End Sub

Full Code:

HTML

<asp:DropDownList runat="server" ID="ddlCountry"></asp:DropDownList>

C#

using System;
using System.Data;

namespace Demo
{
    public partial class Default : System.Web.UI.Page
    {
        private DataTable dt = new DataTable();
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!this.IsPostBack)
            {
                dt.Clear();
                dt.Columns.Add("Id");
                dt.Columns.Add("Country");
                var dr = dt.NewRow();
                dr["Id"] = 1;
                dr["Country"] = "India";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 2;
                dr["Country"] = "Australia";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 3;
                dr["Country"] = "Srilanka";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 4;
                dr["Country"] = "Bangladesh";
                dt.Rows.Add(dr);
                dr = dt.NewRow();
                dr["Id"] = 5;
                dr["Country"] = "New Zealand";
                dt.Rows.Add(dr);
                BindDropdownList();
            }
        }
        public void BindDropdownList()
        {
            if (dt.Rows.Count > 0)
            {
                ddlCountry.DataSource = dt;
                ddlCountry.DataTextField = "Country";
                ddlCountry.DataValueField = "Id";
                ddlCountry.DataBind();
            }
            ddlCountry.Items.Insert(0, new ListItem("--Select Country--", "0"));
        }
    }
}

VB.Net

Imports System
Imports System.Data
Imports System.Web.UI
Imports System.Web.UI.WebControls

Namespace Demo
    Public Partial Class [Default]
        Inherits Web.UI.Page
        Private dt As DataTable = New DataTable()
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
            If Not Me.IsPostBack Then
                dt.Clear()
                dt.Columns.Add("Id")
                dt.Columns.Add("Country")
                Dim dr As DataRow = dt.NewRow()
                dr("Id") = 1
                dr("Country") = "India"
                dt.Rows.Add(dr)
                dr = dt.NewRow()
                dr("Id") = 2
                dr("Country") = "Australia"
                dt.Rows.Add(dr)
                dr = dt.NewRow()
                dr("Id") = 3
                dr("Country") = "Srilanka"
                dt.Rows.Add(dr)
                dr = dt.NewRow()
                dr("Id") = 4
                dr("Country") = "Bangladesh"
                dt.Rows.Add(dr)
                dr = dt.NewRow()
                dr("Id") = 5
                dr("Country") = "New Zealand"
                dt.Rows.Add(dr)
                BindDropdownList()
            End If
        End Sub
        Public Sub BindDropdownList()
            If dt.Rows.Count > 0 Then
                ddlCountry.DataSource = dt
                ddlCountry.DataTextField = "Country"
                ddlCountry.DataValueField = "Id"
                ddlCountry.DataBind()
            End If
            ddlCountry.Items.Insert(0, New ListItem("--Select Country--", "0"))
        End Sub
    End Class
End Namespace

Demo Screenshot:

Please mail me at hemanta@webcodespider.net if you want any code solution from me. 

Thank You 😊 

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