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FileStream.Handle Property

Gets the operating system file handle for the file that the current FileStream object encapsulates.

[Visual Basic]
Public Overridable ReadOnly Property Handle As IntPtr
[C#]
public virtual IntPtr Handle {get;}
[C++]
public: __property virtual IntPtr get_Handle();
[JScript]
public function get Handle() : IntPtr;

Property Value

The operating system file handle for the file encapsulated by this FileStream object, or -1 if the FileStream has been closed.

Exceptions

Exception Type Condition
SecurityException The caller does not have the required permission.

Remarks

This property is an operating system handle for use with operating-system-provided system calls (such as ReadFile on Windows). It will not work with C library functions that expect a file descriptor, such as fread.

The operating system handle might have been opened synchronously or asynchronously, depending on which FileStream constructor was called. Use the IsAsync property to discover whether this handle was opened asynchronously. In Win32, this means the handle was opened for overlapped IO, and it requires different parameters to ReadFile and WriteFile.

CAUTION   Data corruption might occur if a FileStream is created, its handle is passed, some operation moves the handle's file pointer, and then the FileStream is used again. Multiple threads cannot safely write to the same file simultaneously, and FileStream buffering code assumes that it exclusively controls the handle. FileStream might throw an IOException if FileStream detects that some other process has moved the file pointer. To avoid this, do not write any data into a portion of the file that FileStream might have buffered, and restore the file pointer to the location it had when methods were last called on FileStream.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

FileStream Class | FileStream Members | System.IO Namespace | Working with I/O | Reading Text from a File | Writing Text to a File

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