Partial Class in C#

Partial classes allow you to split a class's definition over two or more files.

The compiler then combines the partial classes and compiles the combined class, just as if it had been written in a single file. It follows that the partial classes can't contain definitions of the same members.

Partial classes are commonly used to enable an automated tool to produce one partial class and a human programmer to produce another. A windows forms application developed in Visual Studio is a case in point.

Here's a simple example:

public partial class Person
{
    public void DoSomething()
    {
    }
}


public partial class Person
{
    public void DoSomethingElse()
    {
    }
}

The compiler will compile this as though it had been written:

public class Person
{
    public void DoSomething()
    {
    }

    public void DoSomethingElse()
    {
    }
}