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How to: Write Text to a FileĀ 

The following code examples show how to write text to a text file.

The first example shows how to add text to an existing file. The second example shows how to create a new text file and write a string to it. Similar functionality can be provided by the WriteAllText methods.

NoteNote

Visual Basic users may choose to use the methods and properties provided by the My.Computer.FileSystem object for file I/O. For more information, see My.Computer.FileSystem Object.

Example

Imports System
Imports System.IO

Class Test
    Public Shared Sub Main()
        ' Create an instance of StreamWriter to write text to a file.
        Using sw As StreamWriter = New StreamWriter("TestFile.txt")
            ' Add some text to the file.
            sw.Write("This is the ")
            sw.WriteLine("header for the file.")
            sw.WriteLine("-------------------")
            ' Arbitrary objects can also be written to the file.
            sw.Write("The date is: ")
            sw.WriteLine(DateTime.Now)
            sw.Close()
        End Using
    End Sub
End Class
using System;
using System.IO;

class Test 
{
    public static void Main() 
    {
        // Create an instance of StreamWriter to write text to a file.
        // The using statement also closes the StreamWriter.
        using (StreamWriter sw = new StreamWriter("TestFile.txt")) 
        {
            // Add some text to the file.
            sw.Write("This is the ");
            sw.WriteLine("header for the file.");
            sw.WriteLine("-------------------");
            // Arbitrary objects can also be written to the file.
            sw.Write("The date is: ");
            sw.WriteLine(DateTime.Now);
        }
    }
}
Option Explicit On 
Option Strict On
Imports System
Imports System.IO
Public Class TextToFile
    Private Const FILE_NAME As String = "MyFile.txt"
    Public Shared Sub Main()
        If File.Exists(FILE_NAME) Then
            Console.WriteLine("{0} already exists.", FILE_NAME)
            Return
        End If
        Using sw As StreamWriter = File.CreateText(FILE_NAME)
            sw.WriteLine("This is my file.")
            sw.WriteLine("I can write ints {0} or floats {1}, and so on.", 1, 4.2)
            sw.Close()
        End Using
    End Sub
End Class
using System;
using System.IO;
public class TextToFile 
{
    private const string FILE_NAME = "MyFile.txt";
    public static void Main(String[] args) 
    {
        if (File.Exists(FILE_NAME)) 
        {
            Console.WriteLine("{0} already exists.", FILE_NAME);
            return;
        }
        using (StreamWriter sw = File.CreateText(FILE_NAME))
        {
            sw.WriteLine ("This is my file.");
            sw.WriteLine ("I can write ints {0} or floats {1}, and so on.", 
                1, 4.2);
            sw.Close();
        }
    }
}

See Also

Tasks

How to: Create a Directory Listing
How to: Read and Write to a Newly Created Data File
How to: Open and Append to a Log File
How to: Read Text from a File
How to: Read Characters from a String
How to: Write Characters to a String

Reference

StreamWriter
File.CreateText

Concepts

Basic File I/O