Copy (Clone) existing ASP.Net GridView selected row on Button Click using C# and VB.Net

Hi georgeacuster..., 

Please refer below sample.

HTML

<asp:GridView runat="server" ID="gvCustomers" AutoGenerateColumns="false"
    OnSelectedIndexChanged="OnSelectedIndexChanged">
    <Columns>
        <asp:BoundField DataField="CustomerId" HeaderText="ID" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
        <asp:ButtonField Text="Select" CommandName="Select" ButtonType="Button" />
    </Columns>
</asp:GridView>
<br />
<asp:Button Text="Copy" runat="server" OnClick="Copy" />

Namespaces

C#

using System.Data;
using System.Drawing;

VB.Net

Imports System.Data
Imports System.Drawing

Code

C#

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

private void BindGrid()
{
    if (ViewState["Customers"] == null)
    {
        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");
        ViewState["Customers"] = dt;
    }
    this.gvCustomers.DataSource = ViewState["Customers"] as DataTable;
    this.gvCustomers.DataBind();
}

protected void OnSelectedIndexChanged(object sender, EventArgs e)
{
    this.gvCustomers.SelectedRow.BackColor = Color.Cyan;
}

protected void Copy(object sender, EventArgs e)
{
    GridViewRow gvRow = this.gvCustomers.SelectedRow;
    DataTable dt = null;
    if (ViewState["Customers"] != null)
    {
        dt = ViewState["Customers"] as DataTable;
        dt.Rows.Add(gvRow.Cells[0].Text, gvRow.Cells[1].Text, gvRow.Cells[2].Text);
        ViewState["Customers"] = dt;
    }
    this.BindGrid();
}

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()
    If ViewState("Customers") Is Nothing Then
        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")
        ViewState("Customers") = dt
    End If

    Me.gvCustomers.DataSource = TryCast(ViewState("Customers"), DataTable)
    Me.gvCustomers.DataBind()
End Sub

Protected Sub OnSelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    Me.gvCustomers.SelectedRow.BackColor = Color.Cyan
End Sub

Protected Sub Copy(ByVal sender As Object, ByVal e As EventArgs)
    Dim gvRow As GridViewRow = Me.gvCustomers.SelectedRow
    Dim dt As DataTable = Nothing

    If ViewState("Customers") IsNot Nothing Then
        dt = TryCast(ViewState("Customers"), DataTable)
        dt.Rows.Add(gvRow.Cells(0).Text, gvRow.Cells(1).Text, gvRow.Cells(2).Text)
        ViewState("Customers") = dt
    End If

    Me.BindGrid()
End Sub

Screenshot