Public Sub ExportToExcel(ByVal dt As DataTable)
   Try
      Dim oApp As New Excel.Application
      Dim oBook As Excel.Workbook = oApp.Workbooks.Add
      Dim oSheet As Excel.Worksheet =  CType(oBook.Worksheets(1), _
        Excel.Worksheet)
 
      oApp.Visible = False
 
      With oSheet
         Dim c As Long = Asc("A")
         For Each dc As DataColumn In dt.Columns
            .Range(C hr(c) & "1").Value = dc.ColumnName.ToString
            .Range(C hr(c) & "1").Font.Bold = True
            c += 1
         Next
 
         Dim i As Long = 2
         For Each dr As DataRow In dt.Rows
            c = Asc("A")
            For Each dc As DataColumn In dt.Columns
               .Range(C hr(c) & i.ToString).Value =  dr.Item(dc.ColumnName)
               c += 1
            Next
            i += 1
         Next
 
         oApp.Visible = True
      End With
   Catch ex As Exception
      MessageBox.Show("Source [" & ex.Source & "] Description  [" & ex.Message _
        & "]")
   End Try
End Sub

ExportToExcel(DataGrid1.DataSource)