When to use StreamReader.ReadBlock()?

Question

Hi,

I would like to know of a situation Read(char[],int,int) fails to return all chars requested while ReadBlock() returns all chars as expected (say when StreamReader works with an instance of a FileStream object).

Thanks.

Answer 1

It's a major issue on network streams particularly if the Streamed data is quite large and the server providing the Stream does so as chunked output (i.e. quite typical with HTTP) since a call to just Read() i.e. the single character read gives -1 once the EOS is reached, calls to Read(char[], int, int) with arguments gets up to the number of characters asked for or less if the EOS is reached and then returns the number of characters read or zero if the EOS has been reached

Whereas ReadBlock() waits for data to be available from the Stream so you never run into this issue.

One other thing to note is that both forms reads a maximum number of characters and are not guaranteed to return that many characters if there aren't that many available

I asked a question on a similar topics some time ago - http://stackoverflow.com/questions/1264952/reading-from-a-httpresponsestream-fails - when I had issues reading from HTTP streams