Itemupdating event not
If you wish to modify a property value on the list item during the event, the value should be updated in After Properties property of the properties parameter.
Share Point reads these values from the event parameter and modifies the item accordingly when the actual operation runs (e.g.
Turning off the Require Check Out option is a great quick fix if you don’t require the item to be checked out in order for it to be edited.
But that option exists to be used, and some people really do need it.
Instead of writing more paragraphs I can use tabular to explain, I think this will be easy to understand.
Next, let’s look at what happens when the user adds a document when the Require Check Out option is enabled.
If you find yourself in this situation, then you’ll have to solve the problem in code.
Fortunately, there is a relatively simple way to check whether the Item Updating and Item Updated events are firing in response to a check-in outlined in Knowledgebase Article 939307.
It appears as though they are firing twice in this situation because Share Point is updating the properties on the document and then checking it in on the same request.
If you were to check the document out and edit the properties on the document, you would see the Item Updating and Item Updated events fire once.For example, if you define an instance level variable in the class to store data in the As per the first look of Developers, we say simply, Item Updating and Item Updated events are fire twice when we adding a document to a document library that has the Require Check Out option enabled.This is not either issue with Share Point or issue with Custom Code.You just have to check to see if the vti_sourcecontrolcheckedoutby property on the item was cleared: will not.