partial type (C# Reference)

Partial type definitions allow for the definition of a class, struct, interface, or record to be split into multiple files.

In File1.cs:

namespace PC
{
    partial class A
    {
        int num = 0;
        void MethodA() { }
        partial void MethodC();
    }
}

In File2.cs the declaration:

namespace PC
{
    partial class A
    {
        void MethodB() { }
        partial void MethodC() { }
    }
}

Remarks

Splitting a class, struct or interface type over several files can be useful when you are working with large projects, or with automatically generated code such as that provided by the Windows Forms Designer. A partial type may contain a partial method. For more information, see Partial Classes and Methods.

C# language specification

For more information, see the C# Language Specification. The language specification is the definitive source for C# syntax and usage.

See also