Article
11/18/2011

FileStream Constructor (String, FileMode, FileAccess, FileShare)

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When it is called by trusted applications, initializes a new instance of the FileStream class with the specified path, creation mode, read/write permission, and sharing permission.

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

Syntax

'Declaration
<SecuritySafeCriticalAttribute> _
Public Sub New ( _
    path As String, _
    mode As FileMode, _
    access As FileAccess, _
    share As FileShare _
)

[SecuritySafeCriticalAttribute]
public FileStream(
    string path,
    FileMode mode,
    FileAccess access,
    FileShare share
)

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.

share
Type: System.IO.FileShare
A FileShare constant that determines how the file will be shared by processes.

Exceptions

Exception	Condition
ArgumentNullException	path is nulla 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 system is running Windows 98 or Windows 98 Second Edition and share is set to FileShare.Delete. -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

Platform Notes

Silverlight for Windows Phone

This member has a SecurityCriticalAttribute attribute on Silverlight for Windows Phone, because the attribute was present in Silverlight 3. This attribute restricts this member to internal use. Application code that uses this member throws a MethodAccessException.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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