Begins an asynchronous read operation.
Assembly: System (in System.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)] public override IAsyncResult BeginRead( byte array, int offset, int count, AsyncCallback asyncCallback, Object asyncState )
- Type: System.Byte
The byte array to read the data into.
- Type: System.Int32
The byte offset in array at which to begin writing data read from the stream.
- Type: System.Int32
The maximum number of bytes to read.
- Type: System.AsyncCallback
An optional asynchronous callback, to be called when the read is complete.
- Type: System.Object
A user-provided object that distinguishes this particular asynchronous read request from other requests.
An asynchronous read past the end of the stream was attempted, or a disk error occurred.
One or more of the arguments is invalid.
Methods were called after the stream was closed.
The current GZipStream implementation does not support the read operation.
A read operation cannot be performed because the stream is closed.
The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.
Pass the IAsyncResult return value to the EndRead method of the stream to determine how many bytes were read and to release operating system resources used for reading. You can do this either by using the same code that called or in a callback passed to .
The current position in the stream is updated when the asynchronous read or write is issued, not when the I/O operation completes.
Multiple simultaneous asynchronous requests render the request completion order uncertain.
If a stream is closed or you pass an invalid argument, exceptions are thrown immediately from . Errors that occur during an asynchronous read request, such as a disk failure during the I/O request, occur on the thread pool thread and throw exceptions when calling EndRead.
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.