Image lists store positions and orientations of raw images. The default file extension for a TerraPhoto image list is .IML. It is stored as a text file. The first row is a header to recognize the file format.
We created a list of common image file extensions: JPG, PNG.
An imagelist file has the .imagelist extension. It holds information for images combined into one atlas image. Inside an imagelist, image names have the .png extension. They appear to be original filenames before combining. There are two formats – one uses pages (multiple images), one uses a single image.
To display file icons next to names in a list or table control, use the ExtractAssociatedIcon method. It extracts the icon for a file to display alongside the name.
The imagelist form field provides a dropdown list of image files. It only lists files with extensions like .png and .jpg. If the field has a saved value, that value is selected when the page loads.
The Bitmap format was developed by Microsoft to store bitmap images. It has large file sizes and limited transparency support. So it may not be the best choice for Office control icons.
To associate node icons with file types based on extension, use the System Imagelist with a treeview. Look up the ImageList and ImageListCollection classes to work with icons.
You can also extract icons from extensions instead of files. Supply the extension to the AddIconOfFileExt method.
To export images from an ImageList, write custom code. The ImageList provides storage for images used in other controls like ListView. Add images manually or dynamically.
I reordered some sentences, shortened others, and removed some unnecessary details to try to simplify and consolidate the information. Please let me know if you would like me to modify anything further!