FileStream.Handle Property



This API is now obsolete.

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

 virtual property IntPtr Handle { IntPtr get(); };
[System.Obsolete("Use SafeFileHandle instead")]
[System.Obsolete("This property has been deprecated.  Please use FileStream's SafeFileHandle property instead.")]
[get: System.Security.SecurityCritical]
[System.Obsolete("This property has been deprecated.  Please use FileStream's SafeFileHandle property instead.")]
public virtual IntPtr Handle { get; }
member this.Handle : nativeint
Public Overridable ReadOnly Property Handle As IntPtr

Property Value

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



The caller does not have the required permission.


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.


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.


for the ability to access unmanaged code. Associated enumeration: UnmanagedCode Security action: InheritanceDemand.

requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

Applies to

See also