DeflateStream.CopyToAsync(Stream, Int32, CancellationToken) DeflateStream.CopyToAsync(Stream, Int32, CancellationToken) DeflateStream.CopyToAsync(Stream, Int32, CancellationToken) Method


Asynchronously reads the bytes from the current Deflate stream and writes them to another stream, using a specified buffer size.

 override System::Threading::Tasks::Task ^ CopyToAsync(System::IO::Stream ^ destination, int bufferSize, System::Threading::CancellationToken cancellationToken);
public override System.Threading.Tasks.Task CopyToAsync (System.IO.Stream destination, int bufferSize, System.Threading.CancellationToken cancellationToken);
override this.CopyToAsync : System.IO.Stream * int * System.Threading.CancellationToken -> System.Threading.Tasks.Task


Stream Stream Stream

The stream to which the contents of the current Deflate stream will be copied.

Int32 Int32 Int32

The size, in bytes, of the buffer. This value must be greater than zero. The default size is 81920.

CancellationToken CancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is None.


A task that represents the asynchronous copy operation.


The CopyToAsync method enables you to perform resource-intensive I/O operations without blocking the main thread. This performance consideration is particularly important in a Windows 8.x Store app or desktop app where a time-consuming stream operation can block the UI thread and make your app appear as if it is not working. The async methods are used in conjunction with the async and await keywords in Visual Basic and C#.

If the operation is canceled before it completes, the returned task contains the TaskStatus.Canceled value for the Task.Status property.

Copying begins at the current position in the current Deflate stream.

Applies to