GridLookUpEdit问题

假设tb_store表中有两列bianh和ckname，数据如下
01 原料仓库
02 半成品仓库
03 成品仓库
在窗体的GridLookUpEdit1绑定了这两列，在窗体上都能正确显示出来，但是当我在GridLookUpEdit1中输入01后选择后，我想取的是ckname的值，DisplayMember，ValueMember我都设置了，但是怎么还是01 呢？希望各位给点指点，是不是还有其他需要注意的设置，以下是自己写的代码

Dim usersqlstr = "select bianh,ckname from tb_store order by bianh"
objDataAdpter = New SqlDataAdapter(usersqlstr, objSqlConnection)
Dim objtable As New DataTable()
objDataAdpter.Fill(objtable)
Me.BindingSource1.DataSource = objtable
Me.GridLookUpEdit1.Properties.DataSource = BindingSource1
objtable.Columns("bianh").Caption = "编号"
objtable.Columns("ckname").Caption = "仓库名称"
Me.GridLookUpEdit1.Properties.DisplayMember = "bianh"
Me.GridLookUpEdit1.Properties.ValueMember = "ckname"
GridLookUpEdit1.Properties.AutoComplete = True
GridLookUpEdit1.Properties.ImmediatePopup = True
GridLookUpEdit1.Properties.TextEditStyle = DevExpress.XtraEditors.Controls.TextEditStyles.Standard