Export (0) Print
Expand All
This topic has not yet been rated - Rate this topic

File.AppendAllText Method (String, String, Encoding)

Appends the specified string to the file, creating the file if it does not already exist.

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

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



The file to append the specified string to.


The string to append to the file.


The character encoding to use.

Exception typeCondition




path is a null reference (Nothing in Visual Basic).






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 and a file path, this method opens the specified file, appends the string to the end of the file using the specified encoding, and then closes the file. The file handle is guaranteed to be closed by this method, even if exceptions are raised.

The following code example demonstrates the use of the AppendAllText method to add extra text to the end of 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;

class Test
    public static void Main()

        // This text is added only once to the file.
        if (!File.Exists(path))
            // Create a file to write to.
            string createText = "Hello and Welcome" + Environment.NewLine;
            File.WriteAllText(path, createText);

        // if it is not deleted.
        string appendText = "This is extra text" + Environment.NewLine;
        File.AppendAllText(path, appendText);

        // Open the file to read from.
        string readText = File.ReadAllText(path);



.NET Framework

Supported in: 3.0, 2.0
Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

© 2014 Microsoft. All rights reserved.