Pro C# 2010 and the .NET 4 Platform, Fifth Edition

5.11. Understanding Partial Types

Last but not least, it is important to understand the role of the C# partial keyword. A production level class could very easily consist of hundreds and hundreds of lines of code. As well, given that a typical class is defined within a single *.cs file, you could end up with a very long file indeed. When you are creating your classes, it is often the case that much of the code can be basically ignored once accounted for. For example, field data, properties, and constructors tend to remain as-is during production, while methods tend to be modified quite often.

If you wish, you can partition a single class across multiple C# files, to isolate the boilerplate code from more readily useful members. To illustrate, ...