Set focus to ASP.Net GridView footer TextBox on Button Click using C# and VB.Net

Hi Makumbi,

Please refer below sample.

Note: For this sample i have used temporary DataTable. For more details refer How to create Temporary Table in ASP.Net using C# and VB.Net.

HTML 

<asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false" ShowFooter="true">
    <Columns>
        <asp:BoundField DataField="CustomerId" HeaderText="Customer Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:TemplateField HeaderText="Country">
            <ItemTemplate>
                <asp:Label ID="lblCountry" Text='<%# Eval("Country") %>' runat="server" />
            </ItemTemplate>
            <FooterTemplate>
                <asp:TextBox runat="server" ID="txtCountry" />
            </FooterTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}

private void BindGrid()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] {
                        new DataColumn("CustomerId", typeof(int)),
                        new DataColumn("Name"),
                        new DataColumn("Country")
    });
    dt.Rows.Add(1, "John Hammond", "United States");
    dt.Rows.Add(2, "Mudassar Khan", "India");
    dt.Rows.Add(3, "Suzanne Mathews", "France");
    dt.Rows.Add(4, "Robert Schidner", "Russia");
    this.gvCustomers.DataSource = dt;
    this.gvCustomers.DataBind();
}

protected void Submit(object sender, EventArgs e)
{
    string country = (gvCustomers.FooterRow.FindControl("txtCountry") as TextBox).Text;
    if (string.IsNullOrEmpty(country))
    {
        (gvCustomers.FooterRow.FindControl("txtCountry") as TextBox).Focus();
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGrid()
    End If
End Sub

Private Sub BindGrid()
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("CustomerId", GetType(Integer)), New DataColumn("Name"), New DataColumn("Country")})
    dt.Rows.Add(1, "John Hammond", "United States")
    dt.Rows.Add(2, "Mudassar Khan", "India")
    dt.Rows.Add(3, "Suzanne Mathews", "France")
    dt.Rows.Add(4, "Robert Schidner", "Russia")
    Me.gvCustomers.DataSource = dt
    Me.gvCustomers.DataBind()
End Sub

Protected Sub Submit(ByVal sender As Object, ByVal e As EventArgs)
    Dim country As String = (TryCast(gvCustomers.FooterRow.FindControl("txtCountry"), TextBox)).Text

    If String.IsNullOrEmpty(country) Then
        TryCast(gvCustomers.FooterRow.FindControl("txtCountry"), TextBox).Focus()
    End If
End Sub

Screenshot