C# Constants:

const int MAX_PATH = 260;

VB Constants:

Const MAX_PATH As Integer = 260

Notes:

This is the maximum number of characters, usually including a null terminator, of a standard fully-pathed filename for most Windows API functions that operate on filenames (and a few .NET ones, such as Assembly.LoadFrom). Those that fill a buffer with a filename, such as GetTempFileName, expect a buffer of exactly this length. Some functions, such as CreateFile, can be made to accept longer filenames by using the "\\?\" syntax.