What control is this? ("Open" Button with Drop Down)

Question

The "Open" button on the open file dialog used in certain windows applications includes a dropdown arrow with a list of additional options -- namely "Open with..".

I haven't seen this in every windows application, so you may have to try a few to get it, but SQL Server Management Studio and Visual Studio 2005 will both show the button that way if you go to the menu and choose File->Open->File...

I want to use a button like this with a built-in list in one of my applications, but I can't find the control they're using anywhere in visual studio. I should clarify that I'm looking for that specific button, not the entire dialog. Any thoughts?

Answer 1

I don't think there's a built-in control that can do it in .NET. I'm poking around in the MSDN documentation for the standard Windows Button control, but it doesn't look like it's there.

I did find a Code Project article with a custom implementation; this might help a little.

Answer 2

I've not familiar with using either of these, but try searching msdn for splitbutton or dropdownbutton. I think those are similar to what you're looking for.

Answer 3

I think what you are looking for is called a toolStripSplitButton. It is only available in a toolStrip. But you can add a toolStripContainer anywhere on your form and then put the toolStrip and toolStripSplitButton inside your container.

You won't want to show the grips so you'll want to set your gripMargin = 0. You can also set your autosize=true so that the toolstrip conforms to your button. The button will just look like a normal button (except for the split part) on your form.

Answer 4

Since I found the control in Windows itself, I was hoping to find it built-in somewhere already so I didn't have to add anything to my code-base to use it. But the split button at this link (found via the msdn suggestion) looks pretty promising.
http://blogs.msdn.com/jfoscoding/articles/491523.aspx

I'll try it later myself, but does anyone know if it will handle visual styles well?

Answer 5

Here's my split button implementation. It does not draw the arrow, and the focus/unfocus behavior is a little different.

Both mine and the originals handle visual styles and look great with Aero.

Based on http://wyday.com/blog/csharp-splitbutton

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
using System.Drawing;
using System.ComponentModel;
using System.Diagnostics;

// Original: http://blogs.msdn.com/jfoscoding/articles/491523.aspx
// Wyatt's fixes: http://wyday.com/blog/csharp-splitbutton
// Trimmed down and redone significantly from that version (Nick 5/6/08)
namespace DF
{
    public class SplitButton : Button
    {
        private ContextMenuStrip m_SplitMenu = null;
        private const int SplitSectionWidth = 14;
        private static int BorderSize = SystemInformation.Border3DSize.Width * 2;
        private bool mBlockClicks = false;
        private Timer mTimer;

        public SplitButton()
        {
            this.AutoSize = true;
            mTimer = new Timer();
            mTimer.Interval = 100;
            mTimer.Tick += new EventHandler(mTimer_Tick);
        }

        private void mTimer_Tick(object sender, EventArgs e)
        {
            mBlockClicks = false;
            mTimer.Stop();
        }

        #region Properties
        [DefaultValue(null)]
        public ContextMenuStrip SplitMenu
        {
            get
            {
                return m_SplitMenu;
            }
            set
            {
                if (m_SplitMenu != null)
                    m_SplitMenu.Closing -= 
                        new ToolStripDropDownClosingEventHandler(m_SplitMenu_Closing);

                m_SplitMenu = value;

                if (m_SplitMenu != null)
                    m_SplitMenu.Closing += 
                        new ToolStripDropDownClosingEventHandler(m_SplitMenu_Closing);
            }
        }

        private void m_SplitMenu_Closing(object sender, ToolStripDropDownClosingEventArgs e)
        {
            HideContextMenuStrip();
            // block click events for 0.5 sec to prevent re-showing the menu

        }

        private PushButtonState _state;
        private PushButtonState State
        {
            get
            {
                return _state;
            }
            set
            {
                if (!_state.Equals(value))
                {
                    _state = value;
                    Invalidate();
                }
            }
        }

        #endregion Properties

        protected override void OnEnabledChanged(EventArgs e)
        {
            if (Enabled)
                State = PushButtonState.Normal;
            else
                State = PushButtonState.Disabled;

            base.OnEnabledChanged(e);
        }

        protected override void OnMouseClick(MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left)
                return;
            if (State.Equals(PushButtonState.Disabled))
                return;
            if (mBlockClicks)
                return;

            if (!State.Equals(PushButtonState.Pressed))
                ShowContextMenuStrip();
            else
                HideContextMenuStrip();
        }

        protected override void OnMouseEnter(EventArgs e)
        {
            if (!State.Equals(PushButtonState.Pressed) && !State.Equals(PushButtonState.Disabled))
            {
                State = PushButtonState.Hot;
            }
        }

        protected override void OnMouseLeave(EventArgs e)
        {
            if (!State.Equals(PushButtonState.Pressed) && !State.Equals(PushButtonState.Disabled))
            {
                if (Focused)
                {
                    State = PushButtonState.Default;
                }

                else
                {
                    State = PushButtonState.Normal;
                }
            }
        }

        protected override void OnPaint(PaintEventArgs pevent)
        {
            base.OnPaint(pevent);

            Graphics g = pevent.Graphics;
            Rectangle bounds = this.ClientRectangle;

            // draw the button background as according to the current state.
            if (State != PushButtonState.Pressed && IsDefault && !Application.RenderWithVisualStyles)
            {
                Rectangle backgroundBounds = bounds;
                backgroundBounds.Inflate(-1, -1);
                ButtonRenderer.DrawButton(g, backgroundBounds, State);

                // button renderer doesnt draw the black frame when themes are off =(
                g.DrawRectangle(SystemPens.WindowFrame, 0, 0, bounds.Width - 1, bounds.Height - 1);
            }
            else
            {
                ButtonRenderer.DrawButton(g, bounds, State);
            }

            StringFormat format = new StringFormat();
            format.Alignment = StringAlignment.Center;
            format.LineAlignment = StringAlignment.Center;

            g.DrawString(Text, Font, SystemBrushes.ControlText, bounds, format);
        }

        private void ShowContextMenuStrip()
        {
            State = PushButtonState.Pressed;
            if (m_SplitMenu != null)
            {
                m_SplitMenu.Show(this, new Point(0, Height), ToolStripDropDownDirection.BelowRight);
            }
        }

        private void HideContextMenuStrip()
        {
            State = PushButtonState.Normal;
            m_SplitMenu.Hide();
            mBlockClicks = true;
            mTimer.Start();
        }
    }
}

Answer 6

I used the draggable search in Spy++ (installed with VS) to look at the split open button on the file-open dialog of VS.

This revealed that it's an ordinary windows button with a style which includes BS_DEFSPLITBUTTON. That's a magic keyword which gets you to some interesting places, including

http://www.codeplex.com/windowsformsaero/SourceControl/FileView.aspx?itemId=212902&changeSetId=9930

and here

http://msdn.microsoft.com/en-us/library/bb775949.aspx#using_splits

Hope this helps you.

EDIT:

I've actually just tried that code from CodePlex and it does create a split button - but you do have to make sure you've set the button's FlatStyle to 'System' rather than 'Standard' which is the default. I've not bothered to hook-up the event handling stuff for the drop-down, but that's covered in the MSDN link, I think.

Of course, this is Vista-only (but doesn't need Aero enabled, despite the name on codeplex) - if you need earlier OS support, you'll be back to drawing it yourself.