Bind DataTable rows to GridView rows using C# and VB.Net in ASP.Net

Hi jochk12345,

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

HTML

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
<asp:Button Text="Update" runat="server" OnClick="OnUpdate" />

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.AddRange(new System.Data.DataColumn[3] {
            new System.Data.DataColumn("Id"),
            new System.Data.DataColumn("Name"),
            new System.Data.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");
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
}

protected void OnUpdate(object sender, EventArgs e)
{
    System.Data.DataTable dt = new System.Data.DataTable();
    dt.Columns.AddRange(new System.Data.DataColumn[3] {
            new System.Data.DataColumn("Id"),
        new System.Data.DataColumn("Name"),
        new System.Data.DataColumn("Country") });
    dt.Rows.Add(5, "Maria", "Austria");
    dt.Rows.Add(6, "Ana Trujillo", "France");
    dt.Rows.Add(7, "Suzanne Mathews", "Brazil");

    for (int i = 0; i < GridView1.Rows.Count; i++)
    {
        if (dt.Rows.Count > i)
        {
            GridView1.Rows[i].Cells[0].Text = dt.Rows[i]["Id"].ToString();
            GridView1.Rows[i].Cells[1].Text = dt.Rows[i]["Name"].ToString();
            GridView1.Rows[i].Cells[2].Text = dt.Rows[i]["Country"].ToString();
        }
    }
}

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 Data.DataTable = New Data.DataTable()
        dt.Columns.AddRange(New Data.DataColumn(2) {
                            New Data.DataColumn("Id"),
                            New Data.DataColumn("Name"),
                            New Data.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")
        GridView1.DataSource = dt
        GridView1.DataBind()
    End If
End Sub

Protected Sub OnUpdate(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As Data.DataTable = New Data.DataTable()
    dt.Columns.AddRange(New Data.DataColumn(2) {
                        New Data.DataColumn("Id"),
                        New Data.DataColumn("Name"),
                        New Data.DataColumn("Country")})
    dt.Rows.Add(5, "Maria", "Austria")
    dt.Rows.Add(6, "Ana Trujillo", "France")
    dt.Rows.Add(7, "Suzanne Mathews", "Brazil")

    For i As Integer = 0 To GridView1.Rows.Count - 1
        If dt.Rows.Count > i Then
            GridView1.Rows(i).Cells(0).Text = dt.Rows(i)("Id").ToString()
            GridView1.Rows(i).Cells(1).Text = dt.Rows(i)("Name").ToString()
            GridView1.Rows(i).Cells(2).Text = dt.Rows(i)("Country").ToString()
        End If
    Next
End Sub

Screenshot