File.AppendAllText Method (String, String, Encoding)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

When called by trusted applications, appends the specified string to the file, creating the file if it does not already exist.

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

Syntax

'Declaration
Public Shared Sub AppendAllText ( _
    path As String, _
    contents As String, _
    encoding As Encoding _
)

public static void AppendAllText(
    string path,
    string contents,
    Encoding encoding
)

Exception	Condition
ArgumentException	path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by GetInvalidPathChars.
ArgumentNullException	path is nulla null reference (Nothing in Visual Basic).
PathTooLongException	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.
DirectoryNotFoundException	The specified path is invalid (for example, it is on an unmapped drive).
IOException	An I/O error occurred while opening the file.
UnauthorizedAccessException	path specified a file that is read-only. -or- This operation is not supported on the current platform. -or- path specified a directory. -or- The caller does not have the required permission.
FileNotFoundException	The file specified in path was not found.
NotSupportedException	path is in an invalid format.
SecurityException	The caller does not have the required permission.

Supported in: 5, 4

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.