In this article I will explain with an example, how to dynamically add DropDownList in ASP.Net GridView using C# and VB.Net.
The DropDownList will be added inside TemplateField column of GridView in ASP.Net.
Database
Here I am making use of Microsoft’s Northwind Database. You can download it from here.
Namespaces
You will need to import the following namespaces.
C#
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
VB.Net
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
HTML Markup
The HTML Markup contains an ASP.Net GridView with DropDownList in ItemTemplate of TemplateField.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowDataBound="OnRowDataBound">
<Columns>
<asp:BoundField HeaderText="Name" DataField="ContactName" />
<asp:TemplateField HeaderText = "Country">
<ItemTemplate>
<asp:Label ID="lblCountry" runat="server" Text='<%# Eval("Country") %>' Visible = "false" />
<asp:DropDownList ID="ddlCountries" runat="server">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Binding the GridView
The below code binds the ASP.Net GridView with records from the Customers table of the Northwind database.
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
GridView1.DataSource = GetData("SELECT ContactName, Country FROM Customers");
GridView1.DataBind();
}
}
private DataSet GetData(string query)
{
string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
SqlCommand cmd = new SqlCommand(query);
using (SqlConnection con = new SqlConnection(conString))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataSet ds = new DataSet())
{
sda.Fill(ds);
return ds;
}
}
}
}
VB.Net
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not IsPostBack Then
GridView1.DataSource = GetData("SELECT ContactName, Country FROM Customers")
GridView1.DataBind()
End If
End Sub
Private Function GetData(query As String) As DataSet
Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Dim cmd As New SqlCommand(query)
Using con As New SqlConnection(conString)
Using sda As New SqlDataAdapter()
cmd.Connection = con
sda.SelectCommand = cmd
Using ds As New DataSet()
sda.Fill(ds)
Return ds
End Using
End Using
End Using
End Function
Dynamically add DropDownList in ASP.Net GridView
The RowDataBound event of the ASP.Net GridView is used to bind the ASP.Net DropDownList with the Countries form the Northwind database, once the DropDownList is populated, the Country to which the Customer belongs is set as the Selected in the DropDownList.
C#
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
//Find the DropDownList in the Row.
DropDownList ddlCountries = (e.Row.FindControl("ddlCountries") as DropDownList);
ddlCountries.DataSource = GetData("SELECT DISTINCT Country FROM Customers");
ddlCountries.DataTextField = "Country";
ddlCountries.DataValueField = "Country";
ddlCountries.DataBind();
//Add Default Item in the DropDownList.
ddlCountries.Items.Insert(0, new ListItem("Please select"));
//Select the Country of Customer in DropDownList.
string country = (e.Row.FindControl("lblCountry") as Label).Text;
ddlCountries.Items.FindByValue(country).Selected = true;
}
}
VB.Net
Protected Sub OnRowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
If (e.Row.RowType = DataControlRowType.DataRow) Then
'Find the DropDownList in the Row.
Dim ddlCountries As DropDownList = CType(e.Row.FindControl("ddlCountries"), DropDownList)
ddlCountries.DataSource = GetData("SELECT DISTINCT Country FROM Customers")
ddlCountries.DataTextField = "Country"
ddlCountries.DataValueField = "Country"
ddlCountries.DataBind()
'Add Default Item in the DropDownList.
ddlCountries.Items.Insert(0, New ListItem("Please select"))
'Select the Country of Customer in DropDownList.
Dim country As String = CType(e.Row.FindControl("lblCountry"), Label).Text
ddlCountries.Items.FindByValue(country).Selected = True
End If
End Sub
Screenshot
Demo
Downloads
