vb.net+dbgrid(初学),该怎么处理

vb.net+dbgrid(初学)
Dim   conn   As   New   OleDbConnection
                Dim   adapter1   As   New   OleDbDataAdapter
                Dim   dsr   As   DataSet
                conn.ConnectionString   =   "Provider=Microsoft.Jet.OLEDB.4.0;Data   Source= "   &   CurDir()   &   "\book.mdb "
                conn.Open()
                adapter1.SelectCommand.CommandText   =   "select   *   from   manager "
                adapter1.Fill(dsr)
                Me.DataGrid1.DataSource   =   dsr

提示:adapter1.SelectCommand.CommandText   =   "select   *   from   manager "其他信息:   未将对象引用设置到对象的实例

[解决办法]
事先設定datagrid的樣式...