Flush the stream . this is done by writing any buffered output bytes to the underlying output stream and then flushing that stream 刷新当前输出流，将任何缓冲输出的字节输出到此流中。
2.
Gets or sets a value indicating whether to buffer output and send it after the entire page is finished processing 获取或设置一个值，该值指示是否缓冲输出，并在完成处理整个页之后将其发送。
3.
Gets or sets a value indicating whether to buffer output and send it after the entire response is finished processing 获取或设置一个值，该值指示是否缓冲输出，并在完成处理整个响应之后将其发送。
