protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
OleDbConnection cn = new OleDbConnection(ConnectionString);
cn.Open();
cn1 = new OleDbConnection(ConnectionString);
cn1.Open();
OleDbCommand cmd = new OleDbCommand("select * from [Subject]", cn);
OleDbDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
MasterGridView.DataSource = dr;
MasterGridView.DataBind();
dr.Close();
cmd.Dispose();
cn.Dispose();
cn1.Dispose();
cn = cn1 = null;
}
}
protected void MasterGridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{

GridView oGridView = (GridView)e.Row.FindControl("DetailGridView");
if (oGridView != null)
{
OleDbCommand cmd = new OleDbCommand("select top 10 * from Document Where pid = " + MasterGridView.DataKeys[e.Row.RowIndex].Value, cn1);
OleDbDataReader dr1 = cmd.ExecuteReader();
oGridView.DataSource = dr1;
oGridView.DataBind();
dr1.Close();
cmd.Dispose();
}
}
}
}

VB.NET:

Private ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\aspxWeb.mdb;Persist Security Info=True"
Private cn1 As OleDbConnection

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
If Not Page.IsPostBack Then
Dim cn As OleDbConnection = New OleDbConnection(ConnectionString)
cn.Open
cn1 = New OleDbConnection(ConnectionString)
cn1.Open
Dim cmd As OleDbCommand = New OleDbCommand("select * from [Subject]", cn)
Dim dr As OleDbDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
MasterGridView.DataSource = dr
MasterGridView.DataBind
dr.Close
cmd.Dispose
cn.Dispose
cn1.Dispose
cn = cn1 = Nothing
End If
End Sub

Protected Sub MasterGridView_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
If e.Row.RowType = DataControlRowType.DataRow Then
Dim oGridView As GridView = CType(e.Row.FindControl("DetailGridView"), GridView)
If Not (oGridView Is Nothing) Then
Dim cmd As OleDbCommand = New OleDbCommand("select top 10 * from Document Where pid = " + MasterGridView.DataKeys(e.Row.RowIndex).Value, cn1)
Dim dr1 As OleDbDataReader = cmd.ExecuteReader
oGridView.DataSource = dr1
oGridView.DataBind
dr1.Close
cmd.Dispose
End If
End If
End Sub