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FileOpen Method (String, FileMode, FileAccess, FileShare)
Opens a FileStream on the specified path, having the specified mode with read, write, or read/write access and the specified sharing option.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll) Version: 4.0.0.0
Syntax
C#
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public static FileStream Open(
	string path,
	FileMode mode,
	FileAccess access,
	FileShare share
)

Parameters

path
Type: SystemString
The file to open.
mode
Type: System.IOFileMode
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.IOFileAccess
A FileAccess value that specifies the operations that can be performed on the file.
share
Type: System.IOFileShare
A FileShare value specifying the type of access other threads have to the file.

Return Value

Type: FileStream
A FileStream on the specified path, having the specified mode with read, write, or read/write access and the specified sharing option.
Exceptions
ExceptionCondition
ArgumentExceptionpath is a zero-length string, contains only white space, or contains one or more invalid characters as defined by InvalidPathChars.-or- access specified Read and mode specified Create, CreateNew, Truncate, or Append.
ArgumentNullExceptionpath is null.
PathTooLongExceptionThe 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.
DirectoryNotFoundExceptionThe specified path is invalid, (for example, it is on an unmapped drive).
IOExceptionAn I/O error occurred while opening the file.
UnauthorizedAccessExceptionpath 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. -or-mode is Create and the specified file is a hidden file.
ArgumentOutOfRangeExceptionmode, access, or share specified an invalid value.
FileNotFoundExceptionThe file specified in path was not found.
NotSupportedExceptionpath is in an invalid format.
See Also