[VB.NET]vb.net中 listbox 问题

vb.net中 listbox 问题
vb.net中 listbox控件 数据通过数据库绑定 显示多条记录
设为多选后 在界面上选择两条以上记录时 后台怎样能够取得所选记录的值
为什么我取得总是system........之类的
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Me.ListBox1.SelectedItems(0).ToString()
Me.ListBox1.SelectedItems(1).ToString()

这样就行了吧？
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Dim i As Integer

For i = 0 To ListBox1.SelectedItems.Count - 1
MessageBox.Show(Me.ListBox1.SelectedItems(i).ToString())
Next
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listbox 绑定代码
ListBox1.DataSource = Db.OraDataView
ListBox1.DisplayMember = “字段名”

取值
For i As Integer = 0 To ListBox1.SelectedItems.Count - 1
MessageBox.Show(Me.ListBox1.SelectedItems(i).ToString())
Next

显示为：
System.Data.DataRowView

而不是我数据库里的值 这是怎么回事啊
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While Rd.Read()
ListBox1.Items.Add(Rd.Item( "a "))
End While
绑定后再测试没有问题!
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Rd 是什么啊
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Dim Conn As OleDbConnection
Dim Cmd As OleDbCommand
Dim Rd As OleDbDataReader
Dim SQL As String
Dim Adpt As OleDbDataAdapter
Dim Ds As DataSet
Dim Provider = "Provider=Microsoft.Jet.OLEDB.4.0 "
Dim Database = "Data Source= " & Application.StartupPath() & "/db1.mdb "

Conn = New OleDbConnection(Provider & "; " & Database)
Conn.Open() ''打开数据库
SQL = "Select * From one "
Cmd = New OleDbCommand(SQL, Conn)
Rd = Cmd.ExecuteReader()
While Rd.Read()
ListBox1.Items.Add(Rd.Item( "a "))
End While
Rd.Close()
Conn.Close()
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