File.AppendAllText Method (String, String)
Microsoft Silverlight will reach end of support after October 2021. Learn more.
When it is called by trusted applications, appends the specified string to the file, and then closes the file. If the file does not exist, this method creates a file, writes the specified string to the file, then closes the file.
Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Sub AppendAllText ( _
path As String, _
contents As String _
)
public static void AppendAllText(
string path,
string contents
)
Parameters
- path
Type: System.String
The file to append the specified string to.
- contents
Type: System.String
The string to append to the file.
Exceptions
| 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. |
Version Information
Silverlight
Supported in: 5, 4
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.