Stream.CopyToAsync Method (Stream)
Asynchronously reads the bytes from the current stream and writes them to another stream.
Assembly: mscorlib (in mscorlib.dll)
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 Windows 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#.
Copying begins at the current position in the current stream.