How do I... Resize images using GDI+ while preserving their aspect ratio?

There are many projects that require the automatic resizing of an image. A good example of this is a Web site such as Flickr that allows users to upload images. The user-supplied images are resized and a thumbnail version of the image is generated. Zach Smith explains how to use C# and the .NET Framework to implement this resizing and manipulation functionality.

This download is also available as an entry in the TechRepublic How do I... blog.