[VB.net] สอบถามเกี่ยวกับการสร้างคอนโทรล BindingNavigator คะ

    Private Sub btnNewTabpage_Click(sender As Object, e As EventArgs) Handles btnNewTabpage.Click
        NewTab(TextBox1.Text)
        TextBox1.Clear()
    End Sub

    Sub NewTab(Optional tabname As String = "New Tab")
        Dim bindMandatoryNew As New System.Windows.Forms.BindingNavigator
        bindMandatoryNew.Location = New System.Drawing.Point(4, 12)
        bindMandatoryNew.Dock = DockStyle.None
        bindMandatoryNew.Name = "bindMandatoryNew"
        bindMandatoryNew.TabIndex = 4
        bindMandatoryNew.Size = New System.Drawing.Size(309, 25)
        bindMandatoryNew.AddStandardItems()

        Dim bindOptionalNew As New System.Windows.Forms.BindingNavigator
        bindOptionalNew.Location = New System.Drawing.Point(4, 246)
        bindOptionalNew.Dock = DockStyle.None
        bindOptionalNew.Name = "bindOptionalNew"
        bindOptionalNew.TabIndex = 6
        bindOptionalNew.Size = New System.Drawing.Size(309, 25)
        bindOptionalNew.AddStandardItems()

        Dim DataGridMandatory As New System.Windows.Forms.DataGridView
        DataGridMandatory.Location = New System.Drawing.Point(1, 40)
        DataGridMandatory.Size = New System.Drawing.Size(918, 161)
        DataGridMandatory.TabIndex = 3
        DataGridMandatory.ColumnCount = 5
        DataGridMandatory.Columns(0).Name = "ID"
        DataGridMandatory.Columns(1).Name = "Name"
        DataGridMandatory.Columns(2).Name = "Sub"
        DataGridMandatory.Columns(3).Name = "Category"
        DataGridMandatory.Columns(4).Name = "Command"
        DataGridMandatory.Columns(0).AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
        DataGridMandatory.Columns(1).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
        DataGridMandatory.Columns(2).AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
        DataGridMandatory.Columns(3).AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
        DataGridMandatory.Columns(4).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill

        Dim DataGridOptional As New System.Windows.Forms.DataGridView
        DataGridOptional.Location = New System.Drawing.Point(4, 274)
        DataGridOptional.Size = New System.Drawing.Size(918, 161)
        DataGridOptional.TabIndex = 5
        DataGridOptional.ColumnCount = 5
        DataGridOptional.Columns(0).Name = "ID"
        DataGridOptional.Columns(1).Name = "Name"
        DataGridOptional.Columns(2).Name = "Sub"
        DataGridOptional.Columns(3).Name = "Category"
        DataGridOptional.Columns(4).Name = "Command "
        DataGridOptional.Columns(0).AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
        DataGridOptional.Columns(1).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
        DataGridOptional.Columns(2).AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
        DataGridOptional.Columns(3).AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
        DataGridOptional.Columns(4).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill

        Dim tab As New System.Windows.Forms.TabPage
        With tab
            .Controls.Add(bindMandatoryNew)
            .Controls.Add(DataGridMandatory)
            .Controls.Add(bindOptionalNew)
            .Controls.Add(DataGridOptional)

            .Location = New System.Drawing.Point(12, 51)
            .Text = tabname
            .UseVisualStyleBackColor = True
        End With
        Me.TabControl1.Controls.Add(tab)
    End Sub