File.WriteAllLines Method (String, String[], Encoding)

Creates a new file, writes the specified string array to the file using the specified encoding, and then closes the file. If the target file already exists, it is overwritten.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

public static void WriteAllLines (
	string path,
	string[] contents,
	Encoding encoding
public static void WriteAllLines (
	String path, 
	String[] contents, 
	Encoding encoding
public static function WriteAllLines (
	path : String, 
	contents : String[], 
	encoding : Encoding
Not applicable.



The file to write to.


The string array to write to the file.


An Encoding object that represents the character encoding applied to the string array.

Exception typeCondition


path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by InvalidPathChars.


path is a null reference (Nothing in Visual Basic) or contents string is empty.


The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.


The specified path is invalid (for example, it is on an unmapped drive).


An I/O error occurred while opening the file.


path specified a file that is read-only.


This operation is not supported on the current platform.


path specified a directory.


The caller does not have the required permission.


The file specified in path was not found.


path is in an invalid format.


The caller does not have the required permission.

Given a string array and a file path, this method opens the specified file, writes the string array to the file using the specified encoding, and then closes the file.

The following code example demonstrates the use of the WriteAllLines method to write text to a file. In this example a file is created, if it doesn't already exist, and text is added to it.

using System;
using System.IO;
using System.Text;

class Test
    public static void Main()
        string path = @"c:\temp\MyTest.txt";

        // This text is added only once to the file.
        if (!File.Exists(path))
            // Create a file to write to.
            string[] createText = { "Hello", "And", "Welcome" };
            File.WriteAllLines(path, createText, Encoding.UTF8);

        // This text is always added, making the file longer over time
        // if it is not deleted.
        string appendText = "This is extra text" + Environment.NewLine;
        File.AppendAllText(path, appendText, Encoding.UTF8);

        // Open the file to read from.
        string[] readText = File.ReadAllLines(path, Encoding.UTF8);
        foreach (string s in readText)

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0