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FileMode Enumeration
Specifies how the operating system should open a file.

Namespace: CMS.IO
Assembly: CMS.IO (in CMS.IO.dll) Version: 12.0.0
Syntax
C#
public enum FileMode
Members
  Member nameValueDescription
CreateNew1 Specifies that the operating system should create a new file. This requires System.Security.Permissions.FileIOPermissionAccess.Write. If the file already exists, an System.IO.IOException is thrown.
Create2 Specifies that the operating system should create a new file. If the file already exists, it will be overwritten. This requires System.Security.Permissions.FileIOPermissionAccess.Write. System.IO.FileMode.Create is equivalent to requesting that if the file does not exist, use System.IO.FileMode.CreateNew; otherwise, use System.IO.FileMode.Truncate.
Open3 Specifies that the operating system should open an existing file. The ability to open the file is dependent on the value specified by System.IO.FileAccess. A System.IO.FileNotFoundException is thrown if the file does not exist.
OpenOrCreate4 Specifies that the operating system should open a file if it exists; otherwise, a new file should be created. If the file is opened with FileAccess.Read, System.Security.Permissions.FileIOPermissionAccess.Read is required. If the file access is FileAccess.Write then System.Security.Permissions.FileIOPermissionAccess.Write is required. If the file is opened with FileAccess.ReadWrite, both System.Security.Permissions.FileIOPermissionAccess.Read and System.Security.Permissions.FileIOPermissionAccess.Write are required. If the file access is FileAccess.Append, then System.Security.Permissions.FileIOPermissionAccess.Append is required.
Truncate5 Specifies that the operating system should open an existing file. Once opened, the file should be truncated so that its size is zero bytes. This requires System.Security.Permissions.FileIOPermissionAccess.Write. Attempts to read from a file opened with Truncate cause an exception.
Append6 Opens the file if it exists and seeks to the end of the file, or creates a new file. FileMode.Append can only be used in conjunction with FileAccess.Write. Attempting to seek to a position before the end of the file will throw an System.IO.IOException and any attempt to read fails and throws an System.NotSupportedException.
See Also