Back to C# Language Enhancements.Partial Methods allow lighter weight code emitting by the compiler when writing event handlers. For example, a class defining a data entity that has various properties might make calls to a partial event handler ONBeforeChange, OnAfterChange. Unless the coder implemented the partial method in a partial class, the C# compiler would NOT EVEM emit the calls. If virtial methods, abstract methods, or delegates were used - no code might be called, but the metadata for that call would be in the code.
From Wes Dyer's Blog Entry:
Partial methods are methods that enable lightweight event handling.
Here is an example declaration:
partial class C
{
static partial void M(int i);
}There are a few notable things here:
1. Partial methods must be declared within partial classes
2. Partial methods are indicated by the partial modifier
3. Partial methods do not always have a body
4. Partial methods must return void
5. Partial methods can be static
6. Partial methods can have arguments (including this, ref, and params modifiers)
7. Partial methods must be private
For better descriptions see the following well written blog article on the subject: