Asynchronously reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
The buffer to write the data into.
The byte offset in buffer at which to begin writing data from the stream.
The maximum number of bytes to read.
The token to monitor for cancellation requests. The default value is System.Threading.CancellationToken.None.
A task that represents the asynchronous read operation. The value of the TResult parameter contains the total number of bytes read into the buffer. The result value can be less than the number of bytes requested if the number of bytes currently available is less than the requested number, or it can be 0 (zero) if the end of the stream has been reached.