当只有一个具有特定名称的现有文件时禁用删除

Question

我如何隐藏delete.button并使用另一个按钮更改它，并警告您只有1个操作管理器，您无法再次删除。当我的datagridview

中只有一个（Position = Operation manager）时

Imports System.Data.OleDb

Public Class Form5

    Dim conn As New OleDbConnection
    Dim comm As New OleDbCommand
    Dim dr As OleDbDataReader
    Dim query As String

    Private Sub Form5_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Me.LogInTableAdapter.Fill(Me.LogInDataSet.LogIn)

        If conn.State = ConnectionState.Open Then conn.Close()
        conn.ConnectionString = "Provider = Microsoft.ACE.OLEDB.12.0; " & _
        "Data Source = C:\Users\69neers\Desktop\Database\Program\Program\bin\Debug\LogIn.accdb; " & _
        "Persist Security Info=false"
        conn.Open()


        query = "SELECT * FROM LogIn WHERE Uname = '" & UnameTextBox.Text & "'"
        comm.CommandText = query
        comm.Connection = conn
        dr = comm.ExecuteReader

        dr.Read()


        If LogInBindingSource.Count = 1 And dr("Pos") = PosComboBox.Text Then
            btndelete.Enabled = False
            btndelete.Hide()
            btndelalter.Show()
            btndelete.Enabled = False
        Else
            btndelete.Enabled = True
            btndelalter.Hide()
            btndelete.Show()
        End If



        dr.Close()

    End Sub