PipeStream.BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) Method

Definition

Namespace:

System.IO.Pipes

Assembly:

System.IO.Pipes.dll

Source:

PipeStream.Unix.cs

Begins an asynchronous read operation.

public:
 override IAsyncResult ^ BeginRead(cli::array <System::Byte> ^ buffer, int offset, int count, AsyncCallback ^ callback, System::Object ^ state);

public override IAsyncResult BeginRead (byte[] buffer, int offset, int count, AsyncCallback? callback, object? state);

override this.BeginRead : byte[] * int * int * AsyncCallback * obj -> IAsyncResult

Public Overrides Function BeginRead (buffer As Byte(), offset As Integer, count As Integer, callback As AsyncCallback, state As Object) As IAsyncResult

Parameters

buffer

Byte[]

The buffer to read data into.

offset

Int32

The byte offset in buffer at which to begin reading.

count

Int32

The maximum number of bytes to read.

callback

AsyncCallback

The method to call when the asynchronous read operation is completed.

state

Object

A user-provided object that distinguishes this particular asynchronous read request from other requests.

Returns

IAsyncResult

An IAsyncResult object that references the asynchronous read.

Exceptions

ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

offset is less than 0.

-or-

count is less than 0.

ArgumentException

count is greater than the number of bytes available in buffer.

ObjectDisposedException

The pipe is closed.

NotSupportedException

The pipe does not support read operations.

InvalidOperationException

The pipe is disconnected, waiting to connect, or the handle has not been set.

IOException

The pipe is broken or another I/O error occurred.

Remarks

Pass the returned IAsyncResult object to the EndRead method to determine how many bytes were read and to release operating system resources used for reading. EndRead must be called once for every call to BeginRead. This can be done either in the same code that called BeginRead or in a callback that is passed to BeginRead.

Use the CanRead property to determine whether the current PipeStream object supports read operations.

If the pipe is closed or an invalid argument is passed to BeginRead, the appropriate exceptions are raised immediately. Errors that occur during an asynchronous read request occur on the thread pool thread that is performing the request. The exceptions are raised when the code calls the EndRead method.