Updates the file with the current state of the buffer then clears the buffer.
Assembly: mscorlib (in mscorlib.dll)
Since a buffer can be used for either reading or writing, but not both simultaneously, Flush performs two functions. First, any data previously written to the buffer is copied to the file and the buffer is cleared. Second, if CanSeek is true and data was previously copied from the file to the buffer for reading, the current position within the file is decremented by the number of unread bytes in the buffer. The buffer is then cleared.