Lesson # 14. Working with Files. Reading from a file

• Create a program to output the contents of the file to the console window (the numbers can be outputted separated by whitespaces within a single line). You should use BinaryReader class.
• Download the file L01.dat and place it into your work folder (~/Lesson_14Lab1/bin/Debug). There are 15 integer numbers written in the file.
• You should use the using statement while working with an already opened file. Then, regardless of the success of working with an open file, it will always be closed.

using (var fs = new FileStream(path, FileMode.Create)) { ... }

using (var fs = new FileStream(path, FileMode.Create)) { ... }

• Develop a program with exception handling:
  • To prevent the program from «crashing» and not scare the user, add exception handling — the try..catch block. The using statement must be inside the try..catch block.

  ... try { ... } catch (IOException e) { Console.WriteLine($"Error to read from the file: {e.Message}"); }

  ... try { ... } catch (IOException e) { Console.WriteLine($"Error to read from the file: {e.Message}"); }

• Change the name of the file within the program code. Run the application and check the output. Change the name again to the previous one.
• It isn’t necessary to create methods here.

Expected output:

The data from the file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

+++++++++++++
The data from the file:
error to read from file: Файл 'C:\Users\User\Documents\Visual Studio 2015\Projects\L14_Lab1\bin\Debug\L02.dat' не найден

 
[Solution and Project name: Lesson_14Lab1, file name L14Lab1.cs]

• Download the file L01.dat. There are integer numbers written in the file. Print these numbers to the console window by N numbers in each line (N is entered (N > 0) and has a default value = 10). You must use BinaryReader class. For an empty file, output the «empty file» message.
• There can be multiple try..catch blocks and each of them can handle different errors. Write your code so that one try..catch block handles errors that occur when opening a file, and another block handles errors that occur when working with an already opened file.
• Then the program structure should be as follows:

... try { using ( ... ) using ( ... ) { try { // work with opened file... } catch { // handling an error of working with already opened file } } catch { // handling an error of opening file }

... try { using ( ... ) using ( ... ) { try { // work with opened file... } catch { // handling an error of working with already opened file } } catch { // handling an error of opening file }

• Create a method with two parameters to do the task. The signature of the method:

static void PrintFileInRows(string path, int N=10)

static void PrintFileInRows(string path, int N=10)

• Check to see if the try..catch blocks work properly. Modulate an error while working with already opened file, and error with a name of the file. After checking, return the previous (right) code, and make the comments of the wrong code.

Expected output:

Please input N:
3
1 2 3
4 5 6
7 8 9
10 11 12
13 14 15
+++++++++++++
Please input N:
3
Error to read from the file: Файл 'c:\users\user\documents\visual studio 2015\Projects\L_14Lab2\bin\Debug\L02.dat' не найден.
+++++++++++++
Please input N:
3
1 2 3
4 5 6
7 8 9
10 11 12
13 14 15 
Error working with file: Чтение после конца потока невозможно.

 
[Solution and Project name: Lesson_14Lab2, file name L14Lab2.cs]