这个函数是获取数据填充到listbox的代码，当从数据库删除一个数据后，Dim dr As DataRow = dt.Rows(0)就出错了，显示0处没有任何行   
Private Sub getUser(ByVal id As String)
        Dim sql As String = "select * from [user] where UserId='" & id.Trim() & "'"
        Dim dt As DataTable = sample.GetDataTable(sql)
        Dim dr As DataRow = dt.Rows(0)
        If dt.Rows.Count <> 0 Then
            Me.tbId.Text = dr("UserId").ToString().Trim()
            Me.tbName.Text = dr("Username").ToString().Trim()
            Me.setcheck(dr("purview").ToString().Trim())
            Try
            Catch ex As Exception
                sample.WriteErr(ex)
            End Try
        End If
    End Sub

Private Sub getUser(ByVal id As String)
        Dim sql As String = "select * from [user] where UserId='" & id.Trim() & "'"
        Dim dt As DataTable = sample.GetDataTable(sql)
if dt.rows.count>0 then
Dim dr As DataRow = dt.Rows(0)
        If dt.Rows.Count <> 0 Then
            Me.tbId.Text = dr("UserId").ToString().Trim()
            Me.tbName.Text = dr("Username").ToString().Trim()
            Me.setcheck(dr("purview").ToString().Trim())
            Try
            Catch ex As Exception
                sample.WriteErr(ex)
            End Try
        End If
end if
end sub

谢谢啊,问题是解决了,但是我删除的listbox里的索引出问题了,假设我的列表里有1,2,3,4,5这几个数,当我删除了3这个数,4的索引就会指向3了 ,很郁闷,3里面空的,甚么也没有了!

也就是说，我怎么删除listbox里的索引值,我的删除代码是这样的
Private Function DelUser(ByVal id As String) As Boolean
        Dim flag As Boolean = True
        Try
            Dim sql As String = "delete from [user] where UserId='" & id.Trim() & "'"
            Dim sqlcmd As New SqlCommand(sql, sample.sqlcon)
            sample.sqlcon.Open()
            sqlcmd.ExecuteNonQuery()
        Catch ex As Exception
            sample.WriteErr(ex)
            flag = False
        Finally
            sample.sqlcon.Close()
        End Try
        Return flag
    End Function

谢谢了46167057 我的vqq

比較簡單點的方法，刪除之後，數據重載（相當于刷新）。這樣就不會發生你說的情況
如果一定要刪除的話！
listbox有個ITEMS屬性。那裡面有個方法可以讓你刪除那一行的！