Hiding Inherited Properties and Tasks in Derived Classes

Hiding Properties

When you create a custom control (or any class), you inherit a lot of properties from the base class, most of which are fine. However, particularly in the case of a control derived from UserControl, this brings a lot of properties which may not be relevant to the new control.

For example, if your control never scrolls, then the UserControl inherited property AutoScroll is confusing, and makes your control look unprofessional.

The solution is to hide them. However, actually hiding them took me quite a while to work out:

Create a new property with the same signature as the property you wish to hide, and give it a default getter and setter:

/// <summary>
/// Unused property
/// </summary>
[Browsable(false),
EditorBrowsable(EditorBrowsableState.Never)]
public new bool AutoScroll { get; set; }

The Browsable attribute tells the designer that it should not appear in the Properties window.
The EditorBrowsable attribute tells Intellisense that it should not appear in the autocomplete list.

When you run this, you will find that the AutoScroll property still appears in Intellisense! Annoying, isn't it? Don't worry.
It will only appear in Intellisense within your solution.
If you add a reference to your control library within an different solution, Intellisense will not list the property. (You can however still access it if you type the name in fully. Irritating, but true.)

Hiding Tasks

In addition, you can hide the Task list for a derived control.

In the Visual Studio designer, when you add a component, it shows a "tasks" indicator for some. For example, the TextBox control has a Task which allows the designer to change the Multiline property without accessing the property page:

If you create a class derived from Textbox that doesn't support multiline (a password entry textbox for example), then even if you have "hidden" the Multiline property using the code above, it still appears in the Task.

You can hide it though, by decorating your class with this attribute:

    /// <summary>
    /// Password Textbox: does not expose the entered string.
    /// </summary>
    /// <remarks>
    /// The "Designer" attribute decorating this class is necessary.
    /// This hides the default TextBox Task in the designer - which 
    /// consists of the MultiLine property, which we don't have! 
    /// </remarks>
    [Designer(@"System.Windows.Forms.Design.ControlDesigner, System.Design," +
                " Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")] 
    public class PasswordTextBox : TextBox
        {

This removes the Task indicator in the designer.

History

• 3^rd October, 2011: Original version
• 6^th December, 2015: Added Task hiding and headings
• 6^th December, 2015: Changed title to reflect Task removal