How does C # add multiple icons to an application?

For the Windows XP operating system, browse the file with a list of three types of icons, showing the size of the file icons are 16x16,32x32,48x48 three sizes. Some programs include these three-size icons, and the appropriate size icons are selected and displayed as you browse the files.
How do your own applications with C # have such functionality?

The steps are as follows:
1, create a new icon file *.ico, the project icon to point to this file.
2, in this ICO file, you can right-click on the blank Space, create a number of different resolution of the icon, from 16*16 to 256*256 can be.
These icons are read by the operating system and then used for different sizes.

How does C # add multiple icons to an application?