C# Preprocessor Directives

This section contains information about the following C# preprocessor directives.

#if

#else

#elif

#endif

#define

#undef

#warning

#error

#line

#region

#endregion

#pragma

#pragma warning

#pragma checksum

See the individual topics for more information and examples.

Although the compiler does not have a separate preprocessor, the directives described in this section are processed as if there were one. They are used to help in conditional compilation. Unlike C and C++ directives, you cannot use these directives to create macros.

A preprocessor directive must be the only instruction on a line.

See Also

Concepts

C# Programming Guide

Other Resources

C# Reference