Add new Row to DataTable and display in GridView using C# and VB.Net in ASP.Net

Hi comunidadmexi...,

Check this example. Now please take its reference and correct your code.

HTML

<asp:GridView ID="gvitems" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="sID" HeaderText="sID" ItemStyle-Width="30" />
        <asp:BoundField DataField="contents" HeaderText="contents" ItemStyle-Width="120" />
        <asp:BoundField DataField="sID_contents" HeaderText="sID_contents" ItemStyle-Width="100" />
        <asp:BoundField DataField="sUnita" HeaderText="sUnita" ItemStyle-Width="70" />
    </Columns>
</asp:GridView>
<br />
<asp:Button Text="Add Row" runat="server" OnClick="OnAddRow" />

Namespaces

C#

using System.Data;
using System.Linq;

VB.Net

Imports System.Data
Imports System.Linq

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = GetData();
        gvitems.DataSource = dt;
        gvitems.DataBind();
    }
}

private static DataTable GetData()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[]
    {
        new DataColumn("contents"),
        new DataColumn("sID_contents"),
        new DataColumn("sUnita"),
        new DataColumn("sID")
        {
            DataType = typeof(int),
            AutoIncrement = true,
            AutoIncrementSeed = 1,
            AutoIncrementStep = 1,
        }
    });

    dt.Rows.Add("Near", 0, "D1C");
    dt.Rows.Add("Management", 0, "D1C");
    dt.Rows.Add("Miss", 0, "D1C");

    dt.Rows.Add("Near 1", 1, "D1C");
    dt.Rows.Add("Management 1", 1, "D1C");
    dt.Rows.Add("Miss 1", 1, "D1C");

    dt.Rows.Add("Near 2", 2, "D1C");
    dt.Rows.Add("Management 2", 2, "D1C");
    dt.Rows.Add("Miss 2", 2, "D1C");

    return dt;
}

protected void OnAddRow(object sender, EventArgs e)
{
    DataTable dt = GetData();
    IEnumerable<DataTable> result = from table in dt.AsEnumerable()
                                    group table by table["sID_contents"] into g
                                    select g.CopyToDataTable();

    for (int i = 0; i < result.ToList().Count; i++)
    {
        if (result.ToList()[i].Rows[0]["sID_contents"].ToString() != "0")
        {
            if (result.ToList()[i].Rows.Count <= 3)
            {
                DataRow dr = dt.NewRow();
                dr["contents"] = "Thread " + i;
                dr["sID_contents"] = result.ToList()[i].Rows[0]["sID_contents"];
                dr["sUnita"] = result.ToList()[i].Rows[0]["sUnita"];
                dt.Rows.Add(dr);
            }
        }
    }

    gvitems.DataSource = dt.AsEnumerable().OrderBy(x => x["sID_contents"]).CopyToDataTable();
    gvitems.DataBind();
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = GetData()
        gvitems.DataSource = dt
        gvitems.DataBind()
    End If
End Sub

Private Shared Function GetData() As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() _
    {
        New DataColumn("contents"),
        New DataColumn("sID_contents"),
        New DataColumn("sUnita"),
        New DataColumn("sID") With 
        {
            .DataType = GetType(Integer),
            .AutoIncrement = True,
            .AutoIncrementSeed = 1,
            .AutoIncrementStep = 1
        }
    })
    dt.Rows.Add("Near", 0, "D1C")
    dt.Rows.Add("Management", 0, "D1C")
    dt.Rows.Add("Miss", 0, "D1C")
    dt.Rows.Add("Near 1", 1, "D1C")
    dt.Rows.Add("Management 1", 1, "D1C")
    dt.Rows.Add("Miss 1", 1, "D1C")
    dt.Rows.Add("Near 2", 2, "D1C")
    dt.Rows.Add("Management 2", 2, "D1C")
    dt.Rows.Add("Miss 2", 2, "D1C")
    Return dt
End Function

Protected Sub OnAddRow(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As DataTable = GetData()
    Dim result As IEnumerable(Of DataTable) = From table In dt.AsEnumerable()
                                                Group table By groupByKey = table("sID_contents") Into Group
                                                Select Group.CopyToDataTable()

    For i As Integer = 0 To result.ToList().Count - 1
        If result.ToList()(i).Rows(0)("sID_contents").ToString() <> "0" Then
            If result.ToList()(i).Rows.Count <= 3 Then
                Dim dr As DataRow = dt.NewRow()
                dr("contents") = "Thread " & i
                dr("sID_contents") = result.ToList()(i).Rows(0)("sID_contents")
                dr("sUnita") = result.ToList()(i).Rows(0)("sUnita")
                dt.Rows.Add(dr)
            End If
        End If
    Next

    gvitems.DataSource = dt.AsEnumerable().OrderBy(Function(x) x("sID_contents")).CopyToDataTable()
    gvitems.DataBind()
End Sub

Screenshot