Thank you for using Syncfusion Products.
We have analyzed your requirement for "Pinnable ListBox control in windows form". As this feature is not available in our product, we will consider this as a feature request. If you could confirm some specific details, it would help us to implement the feature in line with your requirement.
Please review the following description of the feature and let us know if it conforms to your requirement.
Need to implement a control to pin the items to the top of the ListBox Items and also support sorting based on the description of pinned an unpinned items.
If our definition of this feature is different from your requirement, then let us know the specific details, so that we can work towards fulfilling your requirement.