If you have ever wanted a Label or TextBox in Windows Forms that performs a little more like on the web, then you've probably figured out that there's no intuitive way to make a Label or TextBox automatically adjust its height to fit the text it contains. While it may not be intuitive, it's definitely not impossible.

In this example, I'll use a TextBox (you could just as easily use a Label) that is docked to the top of a form.To use this, add aTextBox called MyTextBox to the form, and set Dock to DockStyle.Top. Wire up the Resize event of the TextBox to this event handler. 

You can create a ToolStrip CheckBox control by simply extending ToolStripControlHost, but in order to get it to show ToolTip help like all the standard ToolStrip controls, you need to jump through the hoop of adding a MouseHover event handler to bubble up the event. 

In this example, I create a FlowLayoutPanel to hold the new CheckBox so I can add more widgets to the same ToolStrip control later if necessary -- like an image to display a validation error or some other indicator. I create the ToolStripCheckBox by first calling the base contructor (ToolStripControlHost) with a new FlowLayoutPanel. Then I can set some panel properties and add the CheckBox control. 

Finally, I need to add an event handler for the CheckBox's MouseHover event, since this is the event that will cause the ToolTip to display. The event handler simply calls the ToolStripCheckBox's OnMouseHover() method, effectively making it appear that the ToolStripControlHost is raising the event. Show tool tips for this control, and you should see them when you mouse over the CheckBox. 

public partial class ToolStripCheckBox
    : ToolStripControlHost
{
    private FlowLayoutPanel panel;
    private CheckBox chk = new CheckBox();

    public ToolStripCheckBox()
        : base ( new FlowLayoutPanel() ) 
    {
        panel = (FlowLayoutPanel)base.Control;
        panel.BackColor = Color.Transparent;
        panel.Controls.Add( chk );
        chk.MouseHover += new EventHandler( chk_MouseHover );
    }

    void chk_MouseHover( object sender, EventArgs e )
    {
        this.OnMouseHover( e ); 
    }
}

Update 12/30/08:  Vladimir Ilic suggests the following to make the ToolStripCheckBox available through the designer and to show the text: (Thanks, Vladimir!) ToolStripItemDesignerAvailability is in System.Windows.Forms.Design.

[ToolStripItemDesignerAvailability( 
    ToolStripItemDesignerAvailability.ToolStrip )]
[ToolboxBitmap( "..\..\Images\CheckBox.bmp" )]
public class ToolStripCheckBox 
    : ToolStripControlHost
{
    ...
    protected override void OnTextChanged( EventArgs e )
    {
        base.OnTextChanged( e );
        chk.Text = this.Text;
    }
}