Enum FileMode

Contains constants for specifying how the OS should open a file. These will control whether you overwrite a file, open an existing file, or some combination thereof.

To append to a file, use Append (which maps to OpenOrCreate then we seek to the end of the file). To truncate a file or create it if it doesn't exist, use Create.

Namespace: System.IO

Assembly: System.IO.FileSystem.dll

Syntax

public enum FileMode

Fields

Name	Description
Append	Opens the file if it exists and seeks to the end. Otherwise, creates a new file.
Create	Creates a new file. If the file already exists, it is overwritten.
CreateNew	Creates a new file. An exception is raised if the file already exists.
Open	Opens an existing file. An exception is raised if the file does not exist.
OpenOrCreate	Opens the file if it exists. Otherwise, creates a new file.
Truncate	Opens an existing file. Once opened, the file is truncated so that its size is zero bytes. The calling process must open the file with at least WRITE access. An exception is raised if the file does not exist.