Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream. Instead of calling this method, ensure that the stream is properly disposed.
This method calls Stream.Dispose(bool), specifying true to release all resources. You do not have to specifically call the Stream.Close method. Instead, ensure that every System.IO.Stream object is properly disposed. You can declare System.IO.Stream objects within a using block (or Using block in Visual Basic) to ensure that the stream and all of its resources are disposed, or you can explicitly call the Stream.Dispose method.
Flushing the stream will not flush its underlying encoder unless you explicitly call an implementation of Stream.Flush or Close. Setting StreamWriter.AutoFlush to true means that data will be flushed from the buffer to the stream, but the encoder state will not be flushed. This allows the encoder to keep its state (partial characters) so that it can encode the next block of characters correctly. This scenario affects UTF8 and UTF7 where certain characters can be encoded only after the encoder receives the adjacent character or characters.
Attempts to manipulate the stream after the stream has been closed might throw an ObjectDisposedException.