There is nothing like partial classes in Java. You can achieve many of the same benefits using aggregation, delegation, and abstract base classes. (I have caved to peer pressure and eliminated the “thankfully” remark that has generated so much heat in the comments. Evidently that little aside seems to have earned me four downvotes, despite … Read more
That’s a single class defined across multiple declarations, not two different classes. You only need to define the inheritance model in a single declaration, e.g.: public class Foo { } //Bar extends Foo public partial class Bar : Foo { } public partial class Bar { } However, if you were to try the following, … Read more
C# does support the feature of partial methods. These allow a partial class definition to forward declare a method that another part of the partial class can then optionally define. Partial methods have some restrictions: they MUST be of void type (no return) they CANNOT accept out parameters, they can however accept ref parameters they … Read more
Partial classes are primarily for code-generator usage, such as designers – but I use the approach you have cited – in particular when an object implements multiple (non-trivial) interfaces, I find it useful to break it up 1 file per interface implementation. I also commonly have a file for the static methods, which are usually … Read more
EFCore 3 – They FINALLY fixed this! You can now implement OnModelCreatingPartial in a partial class like this. Note the partial keyword on both the class and method: public partial class RRStoreContext : DbContext { partial void OnModelCreatingPartial(ModelBuilder builder) { builder.Entity<RepeatOrderSummaryView>().HasNoKey(); } } If you look at the generated context file – right at the … Read more
Some of differences that will determine whether you want to use a Partial Class or an Extension Method are Partial Class Only works against classes in the same project/assembly Target class has to be marked as partial Has access to the Target class’ fields and protected members Target must be a class implementation Extension Method … Read more
If your problem really is just working with a large class in an editor, the first solution I’d actually look for is a better way to break down the problem. The second solution would be a better editor, preferably one with code folding. That said, there are a couple of ways you might break up … Read more
Keep naming and modifiers consistent across files: public static partial class Facade { // A few general methods that other partial facades will use } public static partial class Facade { // Methods that are specifically for Machine Queries in our Database }
I had a similar problem, with my generated code being created by a DBML file (I’m using Linq-to-SQL classes). In the generated class it calls a partial void called OnCreated() at the end of the constructor. Long story short, if you want to keep the important constructor stuff the generated class does for you (which … Read more
You can’t write a partial class across projects. A partial class is a compile-time-only piece of syntactic sugar – the whole type ends up in a single assembly, i.e. one project. (Your original DAL file would have to declare the class to be partial as well, by the way.)