Waits for the pending asynchronous read operation to complete. (Consider using FileStream.ReadAsync(Byte[], int, int, System.Threading.CancellationToken) instead; see the Remarks section.)
Syntax
Parameters
- asyncResult
Returns
The number of bytes read from the stream, between 0 and the number of bytes you requested. Streams only return 0 at the end of the stream, otherwise, they should block until at least 1 byte is available.
Exceptions
Type Reason ArgumentNullException asyncResult is null. ArgumentException asyncResult was not returned by a call to FileStream.BeginRead(Byte[], int, int, AsyncCallback, object). InvalidOperationException FileStream.EndRead(IAsyncResult) was called multiple times with asyncResult .
Remarks
In the .NET Framework 4 and earlier versions, you have to use methods such as FileStream.BeginRead(Byte[], int, int, AsyncCallback, object) and FileStream.EndRead(IAsyncResult) to implement asynchronous file operations. These methods are still available in the net_v45 to support legacy code; however, the new async methods, such as FileStream.ReadAsync(Byte[], int, int, System.Threading.CancellationToken), FileStream.WriteAsync(Byte[], int, int, System.Threading.CancellationToken), Stream.CopyToAsync(Stream), and FileStream.FlushAsync(System.Threading.CancellationToken), help you implement asynchronous file operations more easily.
FileStream.EndRead(IAsyncResult) must be called exactly for every call to FileStream.BeginRead(Byte[], int, int, AsyncCallback, object). Failing to end a read process before beginning another read can cause undesirable behavior such as deadlock.
This method overrides Stream.EndRead(IAsyncResult).
FileStream.EndRead(IAsyncResult) can be called on every IAsyncResult from FileStream.BeginRead(Byte[], int, int, AsyncCallback, object). Calling FileStream.EndRead(IAsyncResult) tells you how many bytes were read from the stream. FileStream.EndRead(IAsyncResult) will block until the I/O operation has completed.
Requirements
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0