C# 0 The Complete Reference

PART I

C h a p t e r   1 4 :  

U s i n g   I / O  

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PART IPART I

    try {

      while((s = fstr_in.ReadLine()) != null) {

        Console.WriteLine(s);

      }

    } catch(IOException exc) {

      Console.WriteLine("Error Reading File");

      Console.WriteLine(exc.Message);

    }

    fstr_in.Close();

  }

}

In the program, notice how the end of the file is determined. When the reference returned 

by

ReadLine( )

 is null, the end of the file has been reached. Although this approach works, 

StreamReader

 provides an alternative means of detecting the end of the stream: the 

EndOfStream

 property. This read-only property is true when the end of the stream has been 

reached and false otherwise. Therefore, you can use 

EndOfStream

 to watch for the end of a 

file. For example, here is another way to write the 

while

 loop that reads the file:

while(!fstr_in.EndOfStream) {

  s = fstr_in.ReadLine();

  Console.WriteLine(s);

}

In this case, the use of 

EndOfStream

 makes the code a bit easier to understand but does 

not change the overall structure of the sequence. There are times, however, when the use 

of

EndOfStream

 can simplify an otherwise tricky situation, adding clarity and improving 

structure.

As with 

StreamWriter

, in some cases, you might find it easier to open a file directly 

using

StreamReader

. To do so, use this constructor:

StreamReader(string 

fi lename

)

Here, 

filename

 specifies the name of the file to open, which can include a full path specifier. 

The file must exist. If it doesn’t, a