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3.2. Add Any Control to a ToolStrip
The
ToolStrip supports a wide range of
ToolStripItem classes, allowing you to add
everything from buttons and drop-down menus to text-boxes and labels.
However, in some situations you might want to go beyond the standard
options and use other .NET controls, or even place your own custom
controls in the ToolStrip. In order to make this
work, you need to use the ToolStripControlHost.
Note: Want to outfit a ToolStrip with a custom control? Thanks to
the ToolStripControlHost, you can add just about anything.
3.2.1. How do I do that?
There's no way to add standard .NET controls
directly to the ToolStrip, because the
ToolStrip only supports classes that derive from
ToolStripItem. You could create a class that
derives from ToolStripItem to implement a custom
ToolStrip element, but this approach is fairly
complex and tedious. A much simpler approach is to use the
ToolStripControlHost, which can wrap just about
any .NET control.To use the ToolStripControlHost with a
non-ToolStripItem control, just pass the control
object as a constructor argument when you create the
ToolStripControlHost. Then, add the
ToolStripControlHost object to the
ToolStrip. You can use the code in Example 3-1 to add a CheckBox control
to the ToolStrip.Items collection. Figure 3-4 shows the result.
Example 3-1. Adding a Checkbox control to a ToolStrip.Items collection
' Create a CheckBox.
Dim CheckStrip As New CheckBox( )
' Set the CheckBox so it takes the size of its text.
CheckStrip.AutoSize = True
CheckStrip.Text = "Sample CheckBox in ToolStrip"
' Make sure the CheckbBox is transparent (so the
' ToolStrip gradient background shows through).
CheckStrip.BackColor = Color.FromArgb(0, 255, 0, 0)
' Create the ToolStripControlHost that wraps the CheckBox.
Dim CheckStripHost As New ToolStripControlHost(CheckStrip)
' Set the ToolStripControlHost to take the full width
' of the control it wraps.
CheckStripHost.AutoSize = True
' Add the wrapped CheckBox.
ToolStrip1.Items.Add(CheckStripHost)
Figure 3-4. A ToolStrip with a CheckBox
3.2.2. What about...
...customizing
the ToolStripControlHost? If
you're using a
ToolStripControlHost to host another control, you
might want to add properties to the
ToolStripControlHost to expose data from the
hosted control. For example, you could add a Checked property to the
ToolStripControlHost used in this example so that
you could easily set or retrieve the checked state of the wrapped
CheckBox control. In order to use this technique,
you need to create a custom class that derives from
ToolStripControlHost.
3.2.3. Where can I learn more?
The MSDN help reference includes an example with a
ToolStripControlHost that hosts a date control.
For more information, look up the index entry
"ToolStrip
wrapping controlsin.
"
