The first Dropdown style displays a simple list of text items. Create a ContextMenu control and give it some menu items.

Create the Toolbar. Open the Properties window, select the Buttons property, and click the ellipsis to the right. Create a button, set its Style property to DropDownButton and its DropDownMenu property to the context menu you created. Set the button's Text property to whatever text you want it to initially display.

Add code to the context menu's menu items' event handlers. In particular, you may want those commands to set the dropdown button's text to the menu item's text.

This example lets you select some text, a line width, and a color. It then dras a box containing the text using the color and line width. The Form1_Paint event handler draws the rectangle and text.

You select the text using a textual dropdown menu on the toolbar. The menu items mnuTextApple, mnuTextBanana, and so on handle these selections. In this program, those event handlers call subroutine SelectText.

Subroutine SelectText saves the selected text in the variable m_SelectedText, updates the dropdown button's text, and calls Refresh to make the Paint event handler redraw the form.

Private m_SelectedText As String

' Draw a box with some text.
Private Sub Form1_Paint(ByVal sender As Object, ByVal e As _
    System.Windows.Forms.PaintEventArgs) Handles _
    MyBase.Paint
    Dim gr As Graphics = Me.CreateGraphics()
    gr.DrawRectangle( _
        New Pen(m_SelectedColor, m_SelectedLineWidth), _
        10, tbrButtons.Height + 10, ClientSize.Width - 20, _
            ClientSize.Height - tbrButtons.Height - 20)

    Dim new_font As New Font("Times New Roman", 20, _
        FontStyle.Bold, GraphicsUnit.Point)
    gr.DrawString(m_SelectedText, new_font, _
        New SolidBrush(m_SelectedColor), _
        20, tbrButtons.Height + 20)
End Sub

Private Sub mnuTextApple_Click(ByVal sender As _
    System.Object, ByVal e As System.EventArgs) Handles _
    mnuTextApple.Click
    SelectText("Apple")
End Sub
Private Sub mnuTextBanana_Click(ByVal sender As _
    System.Object, ByVal e As System.EventArgs) Handles _
    mnuTextBanana.Click
    SelectText("Banana")
End Sub
Private Sub mnuTextGiraffe_Click(ByVal sender As _
    System.Object, ByVal e As System.EventArgs) Handles _
    mnuTextGiraffe.Click
    SelectText("Giraffe")
End Sub
Private Sub mnuTextMaple_Click(ByVal sender As _
    System.Object, ByVal e As System.EventArgs) Handles _
    mnuTextMaple.Click
    SelectText("Maple")
End Sub

Private Sub SelectText(ByVal text As String)
    m_SelectedText = text
    cboText.Text = text

    ' Redraw.
    Refresh()
End Sub

Create a new context menu and a new dropdown button on the toolbar, and associate the menu with the button as before.

In the Form's Load event handler, use AddHandler to set event handlers for each of the context menu's items' Click events.

' Use one event handler to select all line widths.
AddHandler mnuLineWidth1.Click, AddressOf _
    LineWidthMenu_Click
AddHandler mnuLineWidth2.Click, AddressOf _
    LineWidthMenu_Click
AddHandler mnuLineWidth3.Click, AddressOf _
    LineWidthMenu_Click
AddHandler mnuLineWidth4.Click, AddressOf _
    LineWidthMenu_Click
AddHandler mnuLineWidth5.Click, AddressOf _
    LineWidthMenu_Click

Subroutine SelectLineWidth saves the new width in the m_SelectedLineWidth variable, updates the text displayed on the dropdown button, and calls Refresh to redraw the form.

' The user selected a line width.
Private Sub LineWidthMenu_Click(ByVal sender As _
    System.Object, ByVal e As System.EventArgs) Handles _
    mnuLineWidth1.Click
    Dim menu_item As MenuItem = CType(sender, MenuItem)
    SelectLineWidth(Integer.Parse(menu_item.Text))
End Sub

' Select this line width.
Private Sub SelectLineWidth(ByVal line_width As Integer)
    ' Save the line width for drawing.
    m_SelectedLineWidth = line_width

    ' Display the selected line width.
    cboLineWidth.Text = line_width.ToString

    ' Redraw.
    Refresh()
End Sub

In the context menu, set each menu item's OwnerDraw property to True.

Make an ImageList control and fill it with the images you want to display on the dropdown button. This example displays 16x16 pixel patches of color to represent the selected color. Set the toolbar's ImageList property to this ImageList and set the dropdown button's ImageIndex property to the image you want to display initially.

Because the context menu's items have OwnerDraw set to True, the program needs to respond to two events for each button: MeasureItem and DrawItem. This example uses the same two subroutines for all of the menu items. In the Form's Load event handler, it uses AddHandler to set these event handlers.

AddHandler mnuBlack.MeasureItem, AddressOf _
    ColorMenu_MeasureItem
AddHandler mnuBlack.DrawItem, AddressOf ColorMenu_DrawItem
AddHandler mnuWhite.MeasureItem, AddressOf _
    ColorMenu_MeasureItem
AddHandler mnuWhite.DrawItem, AddressOf ColorMenu_DrawItem
AddHandler mnuRed.MeasureItem, AddressOf _
    ColorMenu_MeasureItem
AddHandler mnuRed.DrawItem, AddressOf ColorMenu_DrawItem
AddHandler mnuGreen.MeasureItem, AddressOf _
    ColorMenu_MeasureItem
AddHandler mnuGreen.DrawItem, AddressOf ColorMenu_DrawItem
AddHandler mnuBlue.MeasureItem, AddressOf _
    ColorMenu_MeasureItem
AddHandler mnuBlue.DrawItem, AddressOf ColorMenu_DrawItem

' Return the size needed for a color 
' dropdown item.
Private Sub ColorMenu_MeasureItem(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.MeasureItemEventArgs) _
    Handles mnuBlack.MeasureItem
    e.ItemWidth = 16
    e.ItemHeight = 16
End Sub

' Draw a color dropdown item.
Private Sub ColorMenu_DrawItem(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.DrawItemEventArgs) _
    Handles mnuBlack.DrawItem
    Dim menu_item As MenuItem = CType(sender, MenuItem)
    e.Graphics.FillRectangle( _
        New SolidBrush(Color.FromName(menu_item.Text)), _
        e.Bounds)
End Sub

' The user selected a color.
Private Sub mnuBlack_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles mnuBlack.Click
    SelectColor(Color.Black, ColorIndex.Black)
End Sub
Private Sub mnuWhite_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles mnuWhite.Click
    SelectColor(Color.White, ColorIndex.White)
End Sub
Private Sub mnuRed_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles mnuRed.Click
    SelectColor(Color.Red, ColorIndex.Red)
End Sub
Private Sub mnuGreen_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles mnuGreen.Click
    SelectColor(Color.Green, ColorIndex.Green)
End Sub
Private Sub mnuBlue_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles mnuBlue.Click
    SelectColor(Color.Blue, ColorIndex.Blue)
End Sub

' Select this color.
Private Sub SelectColor(ByVal color_value As Color, ByVal _
    color_index As ColorIndex)
    ' Save the color for drawing.
    m_SelectedColor = color_value

    ' Display the proper color image.
    cboColor.ImageIndex = color_index

    ' Redraw.
    Refresh()
End Sub