C# : How to read a text file

This is a very basic example where we explain how can we read text files from C#.

We will show three examples:

Example 1:

We will read all the text from a file and store it in a string variable.

For this we will be using C# inbuilt utility function: System.IO.File.ReadAllText

Method signature:

public static string ReadAllText(string path);

Example 2:

We will read all the text from a file line by line and then store each line as an element in a string array.

For this we will be using C# inbuilt utility function: System.IO.File.ReadAllLines

Method signature:

public static string[] ReadAllLines(string path);

We have developed a console application to showcase the feature.The source code for reading file is displayed below:

class Program

    {

        static void Main()

        {

           

            // Read the file as one string.

            string text = System.IO.File.ReadAllText(@"C:\Example1.txt");

            // Display the file contents to the console. Variable text is a string.

            System.Console.WriteLine("*****************EXAMPLE 1*********************");

            System.Console.WriteLine("Contents of Example1.txt = {0} \n \n", text);

            System.Console.WriteLine("*****************EXAMPLE 2*********************");

          

            // Read each line of the file into a string array. Each element

            // of the array is one line of the file.

            string[] lines = System.IO.File.ReadAllLines(@"C:\Example2.txt");

            // Display the file contents by using a foreach loop.

            System.Console.WriteLine("Contents of Example2.txt = ");

            foreach (string line in lines)

            {

                // Use a tab to indent each line of the file.

                Console.WriteLine("\t" + line);

            }

            // Keep the console window open in debug mode.

            Console.WriteLine("Press any key to exit.");

            System.Console.ReadKey();

        }

    }

Example 3:

By Using object of FileStream class and read the file in the form of byte array

class Program

    {

        static void Main(string[] args)

        {

            //Creating the object of FileStream Class and opening the file in Read mode

            FileStream fs = new FileStream(@"C:\Example1.txt", FileMode.Open, FileAccess.Read);

            //Declaring the byte array in which we will read the file

            byte[] bt = new byte[fs.Length];

            //reading the file

            fs.Read(bt,0,bt.Length);

            //Printing the file by converting the byte array in to the string

            Console.WriteLine(System.Text.ASCIIEncoding.ASCII.GetString(bt));

            Console.ReadLine();

           

        }

       

    }

Here is the Screenshot of Output: