Show ASP.Net GridView row on previous row selection using C# and VB.Net

Hi amar,

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

HTML

<asp:GridView ID="gvShow" runat="server" AutoGenerateColumns="false" AutoGenerateSelectButton="true"
    OnSelectedIndexChanged="OnSelectedIndexChanged">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </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)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                    new DataColumn("Name", typeof(string)),
                    new DataColumn("Country",typeof(string)) });
        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");
        gvShow.DataSource = dt;
        gvShow.DataBind();
        for (int i = 1; i < gvShow.Rows.Count; i++)
        {
            gvShow.Rows[i].Visible = false;
        }
    }

}

protected void OnSelectedIndexChanged(object sender, EventArgs e)
{
    int selectedIndex = gvShow.SelectedIndex;
    for (int i = 0; i <= selectedIndex; i++)
    {
        if (gvShow.Rows.Count > selectedIndex + 1)
        {
            gvShow.Rows[i + 1].Visible = true;
        }
    }
}

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 = New DataTable()
        dt.Columns.AddRange(New DataColumn(2) {New DataColumn("Id", GetType(Integer)), New DataColumn("Name", GetType(String)), New DataColumn("Country", GetType(String))})
        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")
        gvShow.DataSource = dt
        gvShow.DataBind()
        For i As Integer = 1 To gvShow.Rows.Count - 1
            gvShow.Rows(i).Visible = False
        Next
    End If
End Sub

Protected Sub OnSelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim selectedIndex As Integer = gvShow.SelectedIndex
    For i As Integer = 0 To selectedIndex
        If gvShow.Rows.Count > selectedIndex + 1 Then
            gvShow.Rows(i + 1).Visible = True
        End If
    Next
End Sub

Screenshot