Svuotare contenuto datagrid

PER SVUOTARE IL DATAGRIDVIEW
        DataGridView1.DataBindings.Clear()
        DataGridView1.DataSource = Nothing
        DataGridView1.DataMember = Nothing
        DataGridView1.Rows.Clear()
        DataGridView1.Refresh()
        Dim ds As New DataSet()
        Dim StringaConnessione As String = "Provider=Microsoft.Jet.OLEDB.4.0;Password="""";User ID=Admin;Data Source=" & Application.StartupPath & "\ore.mdb;Mode=Share Deny None;Extended Properties="""";
              Jet OLEDB:System database="""";Jet OLEDB:Registry Path="""";Jet OLEDBatabase Password="""";Jet OLEDB:Engine Type=5;Jet OLEDBatabase Locking Mode=1;Jet OLEDB:Global Partial Bulk Ops=2;
              Jet OLEDB:Global Bulk Transactions=1;Jet OLEDB:New Database Password="""";Jet OLEDB:Create System Database=False;Jet OLEDB:Encrypt Database=False;Jet OLEDBon't Copy Locale on Compact=False;
              Jet OLEDB:Compact Without Replica Repair=False;Jet OLEDB:SFP=False"
        Dim cn As New OleDbConnection(StringaConnessione)
        cn.Open()

Dim da As New OleDbDataAdapter("SELECT * FROM ore where Causale= '" & ComboBox1.Text & "'", cn)
        da.Fill(ds, "ore")
        Application.DoEvents()
        Me.DataGridView1.DataSource = ds
        Me.DataGridView1.DataMember = "ore"
        cn.Close()
               ds = Nothing

PER SVUOTARE IL DATAGRIDVIEW
DataGridView1.DataBindings.Clear()
DataGridView1.DataSource = Nothing
DataGridView1.DataMember = Nothing
DataGridView1.Rows.Clear()
DataGridView1.Refresh()
Dim ds As New DataSet()
Dim StringaConnessione As String = "Provider=Microsoft.Jet.OLEDB.4.0;Password="""";User ID=Admin;Data Source=" & Application.StartupPath & "\ore.mdb;Mode=Share Deny None;Extended Properties="""";
Jet OLEDB:System database="""";Jet OLEDB:Registry Path="""";Jet OLEDBatabase Password="""";Jet OLEDB:Engine Type=5;Jet OLEDBatabase Locking Mode=1;Jet OLEDB:Global Partial Bulk Ops=2;
Jet OLEDB:Global Bulk Transactions=1;Jet OLEDB:New Database Password="""";Jet OLEDB:Create System Database=False;Jet OLEDB:Encrypt Database=False;Jet OLEDBon't Copy Locale on Compact=False;
Jet OLEDB:Compact Without Replica Repair=False;Jet OLEDB:SFP=False"
Dim cn As New OleDbConnection(StringaConnessione)
cn.Open()

Dim da As New OleDbDataAdapter("SELECT * FROM ore where Causale= '" & ComboBox1.Text & "'", cn)
da.Fill(ds, "ore")
Application.DoEvents()
Me.DataGridView1.DataSource = ds
Me.DataGridView1.DataMember = "ore"
cn.Close()
ds = Nothing