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ThumbnailAttribute Class

Associates an icon with a custom Windows Presentation Foundation (WPF) or Silverlight control in the toolbox for Visual Studio or Expression Blend. 

Inheritance Hierarchy


Namespace:  Microsoft.Windows.Design
Assembly:  Microsoft.Windows.Design.Interaction (in Microsoft.Windows.Design.Interaction.dll)


<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := True)> _
Public NotInheritable Class ThumbnailAttribute _
    Inherits Attribute
[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true)]
public sealed class ThumbnailAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Class, AllowMultiple = true)]
public ref class ThumbnailAttribute sealed : public Attribute
[<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true)>]
type ThumbnailAttribute =  
        inherit Attribute
public final class ThumbnailAttribute extends Attribute

The ThumbnailAttribute type exposes the following members.


  Name Description
Public method ThumbnailAttribute Initializes a new instance of the ThumbnailAttribute class.



  Name Description
Public property ResourceAssembly Gets the assembly that contains the icon image.
Public property ResourceName Gets name of the icon image.
Public property TypeId When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)



  Name Description
Public method Equals Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method GetHashCode Returns the hash code for this instance. (Inherited from Attribute.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Public method IsDefaultAttribute When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
Public method Match When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method ToString Returns a string that represents the current object. (Inherited from Object.)


Explicit Interface Implementations

  Name Description
Explicit interface implemetationPrivate method _Attribute.GetIDsOfNames Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetationPrivate method _Attribute.GetTypeInfo Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetationPrivate method _Attribute.GetTypeInfoCount Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetationPrivate method _Attribute.Invoke Provides access to properties and methods exposed by an object. (Inherited from Attribute.)



Apply the ThumbnailAttribute to assign a toolbox icon to a custom WPF or Silverlight control.

The following steps show how to add an icon representing your control to a type.

  1. Create a design-time metadata assembly for your custom control. For more information, see Walkthrough: Providing Custom Design-time Metadata.

  2. Add an image at the same folder hierarchy as the type you pass to the ThumbnailAttribute. Supported extensions and file types are BMP, GIF, JPG, JPEG and PNG.

    Different designer hosts use different image sizes for the toolbox icon. You can specify a different image for the WPF Designer and Expression Blend by specifying the ThumbnailAttribute in the host-specific metadata assemblies, *.VisualStudio.Design.dll and *.Expression.Design.dll.

    Expression Blend uses 24x24 for the large icon size and 12x12 for the small icon size. The WPF Designer uses 16x16. For more information, see Toolbox Icons.

  3. In the Properties window, set the build action for the image to EmbeddedResource.


    The project sub-folders affect the namespace in which embedded resources are found.

  4. Implement the IProvideAttributeTable interface to add the ThumbnailAttribute to your control’s class. You can reuse the same image across multiple types by applying the same ThumbnailAttribute to multiple controls.

    The ThumbnailAttribute is also used to find a default icon for types added to the Collection Editor or Sub-Properties Editor "new instance" functionality.

Thread Safety

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

See Also


Microsoft.Windows.Design Namespace


Other Resources

Toolbox Icons

Walkthrough: Creating a Custom Toolbox Icon for a Control