DesignerActionPropertyItem Class

Represents a panel item that is associated with a property in a class derived from DesignerActionList. This class cannot be inherited.

Namespace: System.ComponentModel.Design
Assembly: System.Design (in

public sealed class DesignerActionPropertyItem : DesignerActionItem
public final class DesignerActionPropertyItem extends DesignerActionItem
public final class DesignerActionPropertyItem extends DesignerActionItem
Not applicable.

The DesignerActionPropertyItem class represents individual items in a smart tag panel. Each item is typically associated with a property in a class that is derived from the DesignerActionList class and supplied by the component author. The association is maintained through the name of the property, as stored in the MemberName property.

Individual panel items are associated together to form a panel by a call to the GetSortedActionItems method of the DesignerActionList class.

To display the value of the associated property, that property must have a get accessor method; to allow editing, the property must have a set accessor method. The way in which the panel allows direct editing of a property item by the user depends on the supporting type information present for the data type of the associated property. The following table shows the likely scheme.

Property type information

Property item editing user interface (UI)

Has an associated type editor (UITypeEditor)

The type editor associated with the underlying property is displayed for editing the property's value.

Has an associated type converter to a known type (TypeConverter)

The type editor for the known type is displayed for editing the property's value. For example, a type converter to String will likely display a TextBox.

Boolean value

The item is displayed using a binary UI, such as a check mark.

None of the above.

The item is displayed as a non-editable text string using the data type's ToString method.

All fundamental types, such as System.Boolean, and common .NET Framework data types, such as System.String, supply standard type converters and editors. For more information about type converters, see How to: Implement a Type Converter or Generalized Type Conversion. For more information about type editors, see How to: Implement a UI Type Editor.

The following code example demonstrates how to create a collection of DesignerActionItem objects. For a full example of implementing smart tags, see How to: Attach Smart Tags to a Windows Forms Component.

public override DesignerActionItemCollection GetSortedActionItems()
    DesignerActionItemCollection items = new DesignerActionItemCollection();

    //Define static section header entries.
    items.Add(new DesignerActionHeaderItem("Appearance"));
    items.Add(new DesignerActionHeaderItem("Information"));

    //Boolean property for locking color selections.
    items.Add(new DesignerActionPropertyItem("LockColors",
                     "Lock Colors", "Appearance",
                     "Locks the color properties."));
    if (!LockColors)
        items.Add(new DesignerActionPropertyItem("BackColor",
                         "Back Color", "Appearance",
                         "Selects the background color."));
        items.Add(new DesignerActionPropertyItem("ForeColor",
                         "Fore Color", "Appearance",
                         "Selects the foreground color."));

        //This next method item is also added to the context menu 
        // (as a designer verb).
        items.Add(new DesignerActionMethodItem(this,
                         "InvertColors", "Invert Colors",
                         "Inverts the fore and background colors.",
    items.Add(new DesignerActionPropertyItem("Text",
                     "Text String", "Appearance",
                     "Sets the display text."));

    //Create entries for static Information section.
    StringBuilder location = new StringBuilder("Location: ");
    StringBuilder size = new StringBuilder("Size: ");
    items.Add(new DesignerActionTextItem(location.ToString(),
    items.Add(new DesignerActionTextItem(size.ToString(),

    return items;


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

Community Additions