CryptoStream.CopyToAsync(Stream, Int32, CancellationToken) Method
Definition
Important
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Asynchronously reads the bytes from the underlying stream, applies the relevant cryptographic transforms, and writes the result to the destination stream.
public:
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.TaskPublic Overrides Function CopyToAsync (destination As Stream, bufferSize As Integer, cancellationToken As CancellationToken) As TaskParameters
- destination
- Stream
The stream to which the contents of the current stream will be copied.
- bufferSize
- Int32
The size, in bytes, of the buffer. This value must be greater than zero. The default size is 81920.
- cancellationToken
- CancellationToken
The token to monitor for cancellation requests. The default value is None.
Returns
A task that represents the asynchronous copy operation.
Exceptions
destination is null.
buffersize is negative or zero.
Either the current stream or the destination stream is disposed.
The current stream does not support reading, or the destination stream does not support writing.
An error occurred during a cryptographic operation.
The cancellation token was canceled. This exception is stored into the returned task.
Remarks
Copying begins at the current position in the current stream, and does not reset the position of the destination stream after the copy operation is complete.
This method stores in the task it returns all non-usage exceptions that the method's synchronous counterpart can throw. If an exception is stored into the returned task, that exception will be thrown when the task is awaited. Usage exceptions, such as ArgumentException, are still thrown synchronously. For the stored exceptions, see the exceptions thrown by CopyTo(Stream, Int32).
