.NET Windows Forms in a Nutshell

Name

ImageList

Synopsis

This System.ComponentModel.Component wraps a Win32 ImageList control. In theory, this is the best way to manage sets of images for the UI; in practice, there are a few complications, because it tends to reflect the fact that it is a thin wrapper over the Win32 common control, rather than a native part of the .NET Framework.

It offers functions to Draw() a specific image from the list onto a System.Drawing.Graphics surface. Unlike the standard GDI+ image classes, support for alpha channel is limited, unless you are using Windows XP and Common Controls v6. You can, however, set a TransparentColor for basic transparency support.

For interop scenarios, you can retrieve the underlying Handle and determine whether the native list has actually been created yet with the HandleCreated property. (The image resources are lazy-allocated the first time they are needed).

The format of the images can be set and retrieved using the ImageSize and ColorDepth properties. The image data itself can be serialized and deserialized using the ImageStream. Typically, you would be deserializing the data from system resources, and this is all handled for you by the design-time environment.

Finally, the actual images in the list can be accessed through the Images property.

The ImageList control is present because several of the Control classes that wrap Win32 objects are a thin veneer over the raw control, and therefore expose the unmanaged image list functionality. If you want to deal with ...