C# File Handling Programming Examples and Practice Question

In this chapter you will learn:
  • C# File Handling with Programming Example
  • Practice Question and Their Answer.

This chapter is designed for learn C# File Handling with practice question and answer. Your understanding of File Handling will be enhanced more by reading this chapter.

Qu 1. Make a D:\csharp\example.txt file using following class and Read and Write Date and Time. You must make D:\csharp folder before executing this program otherwise it will throw DirectoryNotFound Exception.
  1. FileStream Class
  2. StreamWriter and StreamReader
  3. TextWriter and TextReader
 

Answer

FileStream

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Threading.Tasks;
  6. using System.IO;
  7.  
  8. namespace Example1_FileStream
  9. {
  10.     class Program
  11.     {
  12.         static void Main(string[] args)
  13.         {
  14.             try
  15.             {
  16.                 string file = @"D:\csharp\example.txt";
  17.                 //Creating File
  18.                 FileStream fs = new FileStream(file, FileMode.Create);
  19.                 //Adding current date and time in file
  20.                 byte[] bdata = Encoding.Default.GetBytes(DateTime.Now.ToString());
  21.                 fs.Write(bdata, 0, bdata.Length);
  22.                 Console.WriteLine("Data Added");
  23.                 fs.Close();
  24.                 //Reading File
  25.                 string data;
  26.                 FileStream fsread = new FileStream(file, FileMode.Open, FileAccess.Read);
  27.                 using (StreamReader sr = new StreamReader(fsread))
  28.                 {
  29.                     data = sr.ReadToEnd();
  30.                 }
  31.                 Console.WriteLine(data);
  32.             }
  33.             catch (Exception e)
  34.             {
  35.                 Console.WriteLine(e.Message.ToString());
  36.             }
  37.             Console.ReadKey();
  38.         }
  39.     }
  40. }

Output 
Data Added

17-08-2016 AM 08:27:31

_

StreamWriter and StreamReader

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Threading.Tasks;
  6. using System.IO;
  7.  
  8. namespace Example1_Stream
  9. {
  10.     class Program
  11.     {
  12.         static void Main(string[] args)
  13.         {
  14.             string file = @"D:\csharp\example.txt";
  15.             //Creating and Writting
  16.             using (StreamWriter writer = new StreamWriter(file))
  17.             {                
  18.                 writer.Write(DateTime.Now.ToString());
  19.                 Console.WriteLine("Successfully Added Current Date and Time");
  20.             }            
  21.             //Reading File
  22.             using (StreamReader reader = new StreamReader(file))
  23.             {
  24.                 Console.Write("Reading Current Time : ");
  25.                 Console.WriteLine(reader.ReadToEnd());
  26.             }
  27.             Console.ReadKey();
  28.         }
  29.     }
  30. }

Output 
Successfully Added Current Date and Time

Reading Current Time : 17-08-2016 AM 08:29:00

_

TextWriter and TextReader

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Threading.Tasks;
  6. using System.IO;
  7.  
  8. namespace Example1_Text
  9. {
  10. class Program
  11. {
  12. static void Main(string[] args)
  13. {
  14. string file = @"D:\csharp\example.txt";
  15. //Writting File
  16. using (TextWriter writer = File.CreateText(file))
  17. {
  18. writer.WriteLine(DateTime.Now.ToString());
  19. Console.WriteLine("Successfully Added Current Date and Time");
  20. }
  21. //Reading File
  22. using (TextReader reader = File.OpenText(file))
  23. {
  24. Console.Write("Reading Current Time : ");
  25. Console.WriteLine(reader.ReadToEnd());
  26. }
  27. Console.ReadKey();
  28. }
  29. }
  30. }

Output 
Successfully Added Current Date and Time

Reading Current Time : 17-08-2016 AM 08:31:23

_
Qu 2. Make D:\csharp\example.dat file using BinaryWriter class, store current date and time and read that text using BinaryReader class.

Answer

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Threading.Tasks;
  6. using System.IO;
  7.  
  8. namespace Example2_Binary
  9. {
  10.     class Program
  11.     {
  12.         static void Main(string[] args)
  13.         {
  14.             string file=@"D:\csharp\example.dat";
  15.             using (BinaryWriter writer = new BinaryWriter(File.Open(file, FileMode.Create)))
  16.             {
  17.                 writer.Write("Current Date and Time is : " + DateTime.Now.ToString());
  18.                 writer.Write(true);
  19.             }
  20.             using (BinaryReader reader = new BinaryReader(File.Open(file, FileMode.Open, FileAccess.Read)))
  21.             {
  22.                 Console.WriteLine(reader.ReadString());
  23.             }
  24.             Console.ReadKey();
  25.         }
  26.     }
  27. }

Output 
Current Date and Time is : 17-08-2016 AM 08:33:45

_
Qu 3. Manipulate following string using StringWriter and StringReader class.
"I am reading File Handling at Complete C# Tutorial.com"

Answer

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Threading.Tasks;
  6. using System.IO;
  7.  
  8. namespace Example3_String
  9. {
  10.     class Program
  11.     {
  12.         static void Main(string[] args)
  13.         {
  14.             string text = "I am reading \n File Handling at \n Complete C# Tutorial.com";
  15.             //Writing string into StringBuilder
  16.             StringBuilder sb = new StringBuilder();
  17.             using (StringWriter writer = new StringWriter(sb))
  18.             {
  19.                 //Store Data on StringBuilder
  20.                 writer.WriteLine(text);
  21.                 writer.Flush();
  22.                 writer.Close();
  23.             }
  24.             //Read Entry
  25.             using (StringReader reader = new StringReader(sb.ToString()))
  26.             {
  27.                 Console.WriteLine(reader.ReadToEnd());
  28.             }
  29.             Console.ReadKey();
  30.         }
  31.     }
  32. }

Output 
I am reading

 File Handling at

 Complete C# Tutorial.com

_
Qu 4. Create a Directory D:\example and then create a file in it D:\example\test.txt and store "Hello File Handling" text in it. Then gather information of Directory and File and print them on console.

Answer

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Threading.Tasks;
  6. using System.IO;
  7.  
  8. namespace example_directory
  9. {
  10.     class Program
  11.     {
  12.         static void Main(string[] args)
  13.         {
  14.             CreateDirectory();
  15.             CreateFile();
  16.             Console.ReadKey();
  17.         }
  18.  
  19.         static void CreateDirectory()
  20.         {
  21.             //Creating Directory
  22.             DirectoryInfo dir = new DirectoryInfo("D:\\example");
  23.             try
  24.             {
  25.                 //Check If Directory Exists
  26.                 if (dir.Exists)
  27.                 {
  28.                     Console.WriteLine("Directory Already Exists");
  29.                     Console.WriteLine("Directory Name : " + dir.Name);
  30.                     Console.WriteLine("Path : " + dir.FullName);
  31.                     Console.WriteLine("Directory is created on : " + dir.CreationTime);
  32.                     Console.WriteLine("Directory is Last Accessed on " + dir.LastAccessTime);
  33.                 }
  34.                 //Create New Directory
  35.                 else
  36.                 {
  37.                     dir.Create();
  38.                     Console.WriteLine("Directory Created Successfully. Information of Directory:");
  39.                     Console.WriteLine("Directory Name : " + dir.Name);
  40.                     Console.WriteLine("Path : " + dir.FullName);
  41.                     Console.WriteLine("Directory is created on : " + dir.CreationTime);
  42.                     Console.WriteLine("Directory is Last Accessed on " + dir.LastAccessTime);
  43.                 }                
  44.             }
  45.             catch (DirectoryNotFoundException d)
  46.             {
  47.                 Console.WriteLine(d.Message.ToString());
  48.             }
  49.         }
  50.  
  51.         static void CreateFile()
  52.         {
  53.             FileInfo file = new FileInfo("D:\\example\\test.txt");
  54.             using (StreamWriter sw = file.CreateText())
  55.             {
  56.                 sw.WriteLine("Hello File Handling");
  57.             }
  58.             //Display File Info 
  59.             Console.WriteLine("\n\n******Display File Info******");
  60.             Console.WriteLine("File Create on : " + file.CreationTime);
  61.             Console.WriteLine("Directory Name : " + file.DirectoryName);
  62.             Console.WriteLine("Full Name of File : " + file.FullName);
  63.             Console.WriteLine("File is Last Accessed on : " + file.LastAccessTime);
  64.         }
  65.     }
  66. }

Output 
Directory Created Successfully. Information of Directory:

Directory Name : example

Path : D:\example

Directory is created on : 01-01-1601 AM 05:30:00

Directory is Last Accessed on 01-01-1601 AM 05:30:00



******Display File Info******

File Create on : 17-08-2016 AM 07:42:30

Directory Name : D:\example

Full Name of File : D:\example\test.txt

File is Last Accessed on : 17-08-2016 AM 07:42:30

_

Summary

In this chapter we have tried to teach you File Handling using programming examples and codes. I am sure that your understanding of file handling would be increased. Next chapter have some programming exercise for you. You must resolve the question before proceeding next.

 

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