Represents the collection of column or field references in a content type.
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
If you want to track specific item metadata in a content type, you can reference a column that represents that metadata. However, you cannot create a column within a content type; you must create the column separately and then reference it in the content type definition. As a result, when you add a column to a content type, the content type contains a reference to the column or field rather than the column or field itself.
The column or field reference contains a subset of the properties of the full field definition. These are the properties that you can customize for the column as it exists in the content type.
For more information, see Fields and Field References.
The SPFieldCollection object provides you with a combined view of a column's attributes, as they exist in that content type. Each SPField object represents all the attributes of a column or field definition, combined with those attributes that have been overridden in the field reference for that content type.
When you access an SPField object in a content type, SharePoint Foundation merges the field definition with the field reference and returns the resulting SPField object. This is helpful because you do not have to look up a field definition and all the attributes in that field definition that are overridden by the field reference for that content type.
There is a 1-to-1 correlation between the items in the and SPFieldCollection objects. For each SPFieldLink that you add to a content type, SharePoint Foundation adds a corresponding SPField object that represents the merged view of that column, as it is defined in the content type.