帮我看下这段代码哪里错了好吗??谢谢!!
Private Sub ListBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        Dim curItem As String = ListBox1.SelectedItem.ToString()
        Dim rd As SqlDataReader
        sd.CommandText = sd.CommandText + "where V_num= @num"
        Try
            SqlConnection1.Open()
            Dim cn As New SqlCommand(sd.CommandText, SqlConnection1)
            Dim n As New SqlParameter("@num", SqlDbType.Char, 18)
            cn.Parameters.Add(n)  '加入参数
            n.Value = curItem    '赋值
            cn.ExecuteNonQuery() '执行已经定义好的命令
            rd = cn.ExecuteReader()
            While rd.Read
                num.Text = rd(0)
            End While
            rd.Close()
        Catch ex As Exception
        Finally
            ' rd.Close()
        End Try
    End Sub
其中,CommandText原有"select V_num from vister",我在from_load中,先让ListBox输出num的信息,我希望在ListBox中选择项时,num.text输出相应的信息,可是num.text都没有输出任何信息!!
请大家帮帮忙啊!!谢谢了!!
[此贴子已经被作者于2007-3-31 11:22:37编辑过]

 
											





 
	    


