t’s so weird how so many people ask you the same thing around the same time sometimes, anyway I’ve had some request around on how to create custom properties for Web Parts in SharePoint, more to the point, on how to get them to categorise and appear in the “Modify Web Part” panel.
It’s quite simple actually, just declare the properties and decorate them with attributes like in the following example:
Category(“RSS Aggregator Web Part”),
DisplayName(“URLs of the Feed”),
WebDisplayName(“URLs of the Feed”),
Description(“Please enter the URLs of the feed separated by ‘;’ character.”)]
public string FeedURL
rssUrl = value;
Please note that Category attribute will basically create section for all your properties that carry that attribute value and WebDisplayName will be the name of the property appearing on the panel.