C# 5.0 Programmer's Reference

424 ❘ CHAPTER 18 Streams
Exercises
1. The WriteIntoMemoryStream example program uses Dispose statements to free its
MemoryStream, BinaryWriter, and BinaryReader objects. Rewrite the code with using
statements instead. Which version is easier to read
2. What happens if you don’t dispose of a stream attached to a file A memory stream Which
case is worse
3. Write a program that reads and uses File class methods and streams to save and restore
some text when it starts and stops. When it starts, the program should open a text file (if
it exists) and display its contents in a multiline TextBox. When it is closing, the program
should save the TextBox’s contents into the file, overwriting its previous contents.
4. One way a solution to Exercise 3 can save text is by using a StreamWriter’s Write or
WriteLine method. Which of those methods should you use and why
5. Modify the program you wrote for Exercise 3 to prompt the user to ask if it should overwrite
the file. Take appropriate action when the user clicks Yes, No, or Cancel.
6. Write a program that indicates whether the lines in a file are in alphabetical order. Assume
the file is huge, so the program must read the file one line at a time and compare each line
to the previous one. (That way it needs to store only two lines of text at any given time. It
can also stop if it ever finds two lines out of order.)
7. Modify the program you wrote for Exercise 14-8 so that it writes the primes into the file
Primes.txt in addition to displaying them in a ListBox.
8. Modify the program you wrote for Exercise 7 so that it saves the primes in a binary file
named Primes.dat. When the program starts, it should read that file (if it exists) and
display the saved values in the ListBox. (Hint: The BinaryReader class doesn’t have
an EndOfStream property. To let it know how many values to read, save the number of
primes at the beginning of the file.)
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