Read and Write to a File in C#

  1. Write Data to a File With the File.WriteAllText() Method in C
  2. Read Data From a File With the File.ReadAllText() Method in C
  3. Write Data to a File With the StreamWriter Class in C
  4. Read Data From a File With the StreamReader Class in C

This tutorial will discuss methods to read from and write data to a file in C#.

Write Data to a File With the File.WriteAllText() Method in C

The File class provides functionality for file handling in C#. The File.WriteAllText(path) method can be used to write some string to a file in the path path. The following code example shows us how to write data to a file with the File.WriteAllText() function in C#.

using System;
using System.IO;

namespace write_to_a_file
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = "C:\\File\\file.txt";
            string Text = "Hello, Hi, ByeBye";
            File.WriteAllText(path, Text);
        }
    }
}

file.txt contents:

Hello, Hi, ByeBye

In the above code, we created a text file file.txt inside the path C:\File and wrote the string variable Text to the file.txt file with the File.WriteAllText(path, Text) function in C#.

Read Data From a File With the File.ReadAllText() Method in C

The File.ReadAllText() method can be used to read data from a file in the form of a string variable. The File.ReadAllText() method takes the path of the file as a parameter and returns the contents of the file in string data type. The following code example shows us how to read data from a file with the File.ReadAllText() method in C#.

using System;
using System.IO;

namespace write_to_a_file
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = "C:\\File\\file.txt";
            string readText = File.ReadAllText(path);
            Console.WriteLine(readText);
        }
    }
}

Output:

Hello, Hi, ByeBye

In the above code, we read all the data previously written to the file.txt file inside the C:\File directory with the File.ReadAllText(path) method and displayed it to the user.

Write Data to a File With the StreamWriter Class in C

The StreamWriter class is used to write data to a stream in a particular encoding in C#. The StreamWrite.WriteLine() method can be used to write a string variable to a file. The following code example shows us how to write data to a file with the StreamWriter.WriteLine() method in C#.

using System;
using System.IO;

namespace write_to_a_file
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = "C:\\File\\file.txt";
            string Text = "Hello and Welcome";
            using (StreamWriter writetext = new StreamWriter(path))
            {
                writetext.WriteLine(Text);
            }
        }
    }
}

file.txt contents:

Hello and Welcome

In the above code, we created an object of the StreamWriter class and wrote the string variable Text to the file.txt file inside the C:\File directory with the writetext.WriteLine(Text) function in C#.

Read Data From a File With the StreamReader Class in C

The StreamReader class is used to read data from a stream in a particular encoding in C#. The StreamReader.ReadLine() method can be used to read string data from a file. The following code example shows us how to read data from a file with the StreamReader.ReadLine() method in C#.

using System;
using System.IO;

namespace write_to_a_file
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = "C:\\File\\file.txt";
            using (StreamReader readtext = new StreamReader(path))
            {
                string readText = readtext.ReadLine();
                Console.WriteLine(readText);
            }
        }
    }
}

Output:

Hello and Welcome

In the above code, we created an object of the StreamReader class and read all the data previously written to the file.txt file inside the C:\File directory with the readtext.ReadLine() function and displayed it to the user.

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