Itemupdating properties afterproperties null

The wording is curious here, so I thought I’d take some time to test each combination of common events such as Add, Update and Delete.These were done across a custom list and then a document library.How can we prevent a user from changing a certain column for an item in a list event?

These can apply to Feature events such as Feature Activated, List events such as Field Added, and many others.

I am nothing if not a masterful linguist after a beer or two or more.

Hopefully you know about item event receiver if you are having problems with them firing twice.

Each test involved adding a new item, editing the item and then deleting the item.

Here are the results for a list: No value means that column value in the hash table was not available.

For example, you can hook into the Item Updating event for a document library and prevent a user from changing a certain column.