File Input and Output (Evening)

Here is the WriteFile class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO; //necessary for file creation
//and reading

namespace FileHandling
{
    class WriteFiles
    {
        /// <summary>
        /// This class writes a text file
        /// the constructor takes the path
        /// --the complete file name--
        /// and instantiates the StreamWriter
        /// object that writes the files
        /// </summary>
        private StreamWriter writer;
        public WriteFiles(string path)
        {
            //instantiate the SteamWriteObject
            //its constructor takes the path
            //the true means set the file to append
            //if it exists. If it doesn't exist it
            //will create the file
            //false would mean to write over
            //the file if it exists
            writer = new StreamWriter(path, true);
        }

        public void AddToFile(string line)
        {
            //this uses a method of the StreamWriter
            //that writes a line to the file
            writer.WriteLine(line);
        }

        public void CloseFile()
        {
            //this closes the file
            //if you don't close it
            //you will be unable to access
            //the file
            writer.Close();
        }
    }
}

---

Here is the ReadFile class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;//nescessary for file IO

namespace FileHandling
{
    
    class ReadFile
    {
        /// <summary>
        /// this class reads text files.
        /// It takes the path to the file as a parameter
        /// in the constructor
        /// </summary>
        /// 
        private StreamReader reader;
        private string filePath;

        //constructor takes in the path
        //as parameter
        public ReadFile (string path)
        {
            filePath = path;
           
        }

        public string GetFile()
        {
            //this method gets the file and
            //reads it, returning a string
            string line = null;
            //when dealing with things like files
            //it is a good idea to use a try set
            //It is always possible that the file
            //is not at the specified path
            //or that it is unreadable
            try 
            {
                //get the file from the location
                //indicated by the path
                reader = new StreamReader(filePath);
                //read it all into a string
                //this is not very sophisticated
                //there are other ways to read the file
                line = reader.ReadToEnd();
            }
            catch (FileNotFoundException fnf)
            {
                //the FileNotFoundException is a pre built
                //exception for missing files
                //we throw the exception to the 
                //calling class for display
                throw fnf;
            }
            catch (Exception ex)
            {
                //this catch is for any other kind
                //of error
                throw ex;
            }
            return line;
        }
    }
}

---

Here is the Program class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace FileHandling
{
    class Program
    {
        /// <summary>
        /// I use this class to call the other classes
        /// The WriteStuff() method writes a file
        /// and the ReadStuff() method reads the
        /// file that was just written
        /// </summary>
        /// 
        static void Main(string[] args)
        {
            Program p = new Program();
            p.WriteStuff();
            p.ReadStuff();
           
            Console.ReadKey();
        }

        private void WriteStuff()
        {
            //instantiate WriteFiles and pass the path
            //to its constructor
            WriteFiles write = new WriteFiles(@"C:\temp\MyFile.txt");
            //write something to store in the file
            Console.WriteLine("Enter whatever");
            string stuff = Console.ReadLine();
            //pass what you write to the WriteFiles method AddToFile(string)
            write.AddToFile(stuff);
            //make sure to close the file
            write.CloseFile();
        }

        private void ReadStuff()
        {
            //this try catch will catch the errors
            //thrown by ReadFiles
            try
            { 
                //first we read the file. If it doesn't exist
                //it will throw a file not found exception
                ReadFile read = new ReadFile(@"C:\temp\MyFile.txt");
                //now we read the file into a string
                string myText = read.GetFile();
                //then we display the string
                Console.WriteLine(myText);
            }
            catch(Exception ex)
            {
                //this catches any error and displays
                //the error message
                Console.WriteLine(ex.Message);
                Console.ReadKey();
            }
        }
    }
}