System.IO.Stream.CopyToAsync Method

Asynchronously reads the bytes from the current stream and writes them to another stream.


public System.Threading.Tasks.Task CopyToAsync (Stream destination)


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


A task that represents the asynchronous copy operation.


The Stream.CopyToAsync(Stream) method enables you to perform resource-intensive I/O operations without blocking the main thread. This performance consideration is particularly important in a win8_appname_long app or desktop_appname 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#.

Copying begins at the current position in the current stream.


Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: