我一直在使用一个pos系统 VB.NET 需要一些帮助来解决我面临的问题。
基本上，我使用一个函数 SQL 表中查找与表格中某个类别对应的项目相关的信息 Button .
基本上，所有类别都自动创建到 Form 使用 SQL table。
我想找到一种方法，使用它我将能够以 Buttons 分配给数据库中已在代码中完成的每个类别。
唯一的问题是，按钮形式的旧项目不会被删除，并将留在屏幕上，造成一个问题，我无法看到由类别调用的新项目 Button .
下面是代码示例：

Public Sub Form13_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    Dim point As Integer
    Dim point1 As Integer
    point = 20
    point1 = 100

    Label2.Text = Form12.selected_value
    Dim connection As New MySqlConnection
    connection.ConnectionString = ("host=localhost;user=root;password=;database=pos;")
    connection.Open()
    Dim command As New MySqlCommand("select * from categories", connection)
    Dim reader As MySqlDataReader
    reader = command.ExecuteReader
    Dim perm As String
    While reader.Read()
        Dim button As New Button

        Dim value As String = reader.GetString("category_name")
        perm = reader.GetString("category_name")
        button.Name = value
        button.Text = value
        button.Height = 50
        button.Width = 190
        button.Font = New Font("arial", 11)
        button.Location = New Point(point, point1)
        Me.Controls.Add(button)
        point1 = point1 + 50

        'showing items based on the button that the user clicks
        AddHandler button.Click,
        Sub()
            reader.Close()
            Dim command1 As New MySqlCommand("select * from items where category=@name", connection)
            command1.Parameters.AddWithValue("@name", value)
            reader = command1.ExecuteReader

            'new look for the items to be converted into physical buttons
            Dim point2 As Integer
            Dim point3 As Integer

            point2 = 235
            point3 = 100
            Dim counter As Integer
            counter = 1
            While reader.Read()
                Dim item As String
                Dim category_type As String
                category_type = reader.GetString("category")
                item = reader.GetString("name")

                Dim button1 As New Button
                button1.Name = item
                button1.Text = item
                button1.Height = 50
                button1.Width = 160
                button1.Font = New Font("Arial", 11)
                button1.Location = New Point(point2, point3)
                Me.Controls.Add(button1)
                counter = counter + 1
                Me.Refresh()

                'figure out how to remove buttons when they are not neeeded aka find a way to check when a button is being clicked
                If point2 > 700 Then
                    point2 = 235
                    point3 = point3 + 55
                Else
                    point2 = point2 + 168
                End If
            End While
        End Sub
    End While
End Sub

请帮帮我，因为我已经被这个问题困扰了很长时间了。
我假设可以通过找出用户何时单击不同的类别来解决这个问题，这样就可以使用 button1.Dispose .
包含这些项目的表格的图像已附在下面：