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Stream.EndRead(IAsyncResult) Method


Waits for the pending asynchronous read to complete. (Consider using ReadAsync(Byte[], Int32, Int32) instead.)

 virtual int EndRead(IAsyncResult ^ asyncResult);
public virtual int EndRead (IAsyncResult asyncResult);
abstract member EndRead : IAsyncResult -> int
override this.EndRead : IAsyncResult -> int
Public Overridable Function EndRead (asyncResult As IAsyncResult) As Integer



The reference to the pending asynchronous request to finish.


The number of bytes read from the stream, between zero (0) and the number of bytes requested. ReadAsync returns zero (0) only if zero bytes were requested or if no more bytes will be available because it's at the end of the stream; otherwise, read operations do not complete until at least one byte is available. If zero bytes are requested, read operations may complete immediately or may not complete until at least one byte is available (but without consuming any data).


asyncResult is null.

A handle to the pending read operation is not available.


The pending operation does not support reading.

asyncResult did not originate from a BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) method on the current stream.

The stream is closed or an internal error has occurred.


In the .NET Framework 4 and earlier versions, you have to use methods such as BeginRead and EndRead to implement asynchronous I/O operations. These methods are still available in the .NET Framework 4.5 to support legacy code; however, the new async methods, such as ReadAsync, WriteAsync, CopyToAsync, and FlushAsync, help you implement asynchronous I/O operations more easily.

Call EndRead to determine how many bytes were read from the stream.

EndRead can be called once on every IAsyncResult from BeginRead.

This method blocks until the I/O operation has completed.

Applies to

See also