BufferedStream.EndRead Method (IAsyncResult)
Waits for the pending asynchronous read operation to complete. (Consider using ReadAsync instead; see the Remarks section.)
Assembly: mscorlib (in mscorlib.dll)
The reference to the pending asynchronous request to wait for.
Return ValueType: System.Int32
The number of bytes read from the stream, between 0 (zero) and the number of bytes you requested. Streams only return 0 only at the end of the stream, otherwise, they should block until at least 1 byte is available.
In the .NET Framework 4 and earlier versions, you have to use methods such as BeginRead and EndRead to implement asynchronous file 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, and FlushAsync, help you implement asynchronous file operations more easily.
IAsyncResult to find out how many bytes were read.must be called with this
Available since 4.5