FileStream Constructor (String, FileMode, FileAccess) (System.IO)

.NET Framework Class Library

FileStream Constructor (String, FileMode, FileAccess)

Initializes a new instance of the FileStream class with the specified path, creation mode, and read/write permission.

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

Syntax

Visual Basic (Declaration)

Public Sub New ( _
    path As String, _
    mode As FileMode, _
    access As FileAccess _
)

Visual Basic (Usage)

Dim path As String
Dim mode As FileMode
Dim access As FileAccess

Dim instance As New FileStream(path, mode, _
    access)

public FileStream(
    string path,
    FileMode mode,
    FileAccess access
)

Visual C++

public:
FileStream(
    String^ path, 
    FileMode mode, 
    FileAccess access
)

JScript

public function FileStream(
    path : String, 
    mode : FileMode, 
    access : FileAccess
)

Parameters

path: Type: System..::.String
A relative or absolute path for the file that the current FileStream object will encapsulate.

mode: Type: System.IO..::.FileMode
A FileMode constant that determines how to open or create the file.

access: Type: System.IO..::.FileAccess
A FileAccess constant that determines how the file can be accessed by the FileStream object. This gets the CanRead and CanWrite properties of the FileStream object. CanSeek is true if path specifies a disk file.

Exceptions

Exception	Condition
ArgumentNullException	path is nullNothingnullptra null reference (Nothing in Visual Basic).
ArgumentException	path is an empty string (""), contains only white space, or contains one or more invalid characters. -or- path refers to a non-file device, such as "con:", "com1:", "lpt1:", etc. in an NTFS environment.
NotSupportedException	path refers to a non-file device, such as "con:", "com1:", "lpt1:", etc. in a non-NTFS environment.
ArgumentException	path is an empty string (""), contains only white space, or contains one or more invalid characters.
FileNotFoundException	The file cannot be found, such as when mode is FileMode.Truncate or FileMode.Open, and the file specified by path does not exist. The file must already exist in these modes.
IOException	An I/O error occurs, such as specifying FileMode.CreateNew and the file specified by path already exists. -or- The stream has been closed.
SecurityException	The caller does not have the required permission.
DirectoryNotFoundException	The specified path is invalid, such as being on an unmapped drive.
UnauthorizedAccessException	The access requested is not permitted by the operating system for the specified path, such as when access is Write or ReadWrite and the file or directory is set for read-only access.
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.
ArgumentOutOfRangeException	mode contains an invalid value.

Remarks

The .NET Framework does not support direct access to physical disks through paths that are device names, such as "\\.\PHYSICALDRIVE0 ".

The path parameter can be a file name, including a file on a Universal Naming Convention (UNC) share.

The constructor is given read/write access to the file, and it is opened sharing Read access (that is, requests to open the file for writing by this or another process will fail until the FileStream object has been closed, but read attempts will succeed). The buffer size is set to the default size of 8192 bytes (8 KB).

Note:
path is not required to be a file stored on disk; it can be any part of a system that supports access through streams. For example, depending on the system, this class can access a physical device.

CanSeek is true for all FileStream objects that encapsulate files. If path indicates a device that does not support seeking, the CanSeek property on the resulting FileStream is false. For additional information, see CanSeek.

FileShare.Read is the default for those FileStream constructors without a FileShare parameter.

Caution:
When you compile a set of characters with a particular cultural setting and retrieve those same characters with a different cultural setting, the characters might not be interpretable, and could cause an exception to be thrown.

For a list of common I/O tasks, see Common I/O Tasks.

.NET Framework Security

FileIOPermission
for reading, writing, and appending to files. Associated enumerations: FileIOPermissionAccess..::.Read, FileIOPermissionAccess..::.Write, and FileIOPermissionAccess..::.Append.

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

Reference

Other Resources

File and Stream I/O

How to: Read Text from a File

How to: Write Text to a File