File.Open Method (String, FileMode, FileAccess)

July 28, 2014

Opens a FileStream on the specified path, with the specified mode and access.

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Shared Function Open ( _
	path As String, _
	mode As FileMode, _
	access As FileAccess _
) As FileStream

Parameters

path
Type: System.String
The file to open.
mode
Type: System.IO.FileMode
A FileMode value that specifies whether a file is created if one does not exist, and determines whether the contents of existing files are retained or overwritten.
access
Type: System.IO.FileAccess
A FileAccess value that specifies the operations that can be performed on the file.

Return Value

Type: System.IO.FileStream
An unshared FileStream that provides access to the specified file, with the specified mode and access.

ExceptionCondition
ArgumentException

path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by GetInvalidPathChars.

-or-

access specified Read and mode specified Create, CreateNew, Truncate, or Append.

ArgumentNullException

path is Nothing.

PathTooLongException

The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.

DirectoryNotFoundException

The specified path is invalid, (for example, it is on an unmapped drive).

IOException

An I/O error occurred while opening the file.

UnauthorizedAccessException

path specified a file that is read-only and access is not Read.

-or-

path specified a directory.

-or-

The caller does not have the required permission.

ArgumentOutOfRangeException

mode or access specified an invalid value.

FileNotFoundException

The file specified in path was not found.

NotSupportedException

path is in an invalid format.

Version Notes

Windows Phone

 This member has a SecurityCriticalAttribute attribute. This attribute restricts this member to internal use. Application code that uses this member throws a MethodAccessException.

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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