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File.WriteAllLines Method (String, String())

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

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

'Declaration
Public Shared Sub WriteAllLines ( _
	path As String, _
	contents As String() _
)
'Usage
Dim path As String 
Dim contents As String()

File.WriteAllLines(path, contents)

Parameters

path
Type: System.String

The file to write to.

contents
Type: System.String()

The string array to write to the file.

ExceptionCondition
ArgumentException

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

ArgumentNullException

path or contents is Nothing.

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.

The default behavior of the WriteAllLines method is to write out data using UTF-8 encoding without a byte order mark (BOM). If it is necessary to include a UTF-8 identifier, such as a byte order mark, at the beginning of a file, use the WriteAllLines(String, String(), Encoding) method overload with UTF8 encoding.

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

Imports System
Imports System.IO

Public Class Test
    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt" 
        Dim sw As StreamWriter

        ' This text is added only once to the file. 
        If File.Exists(path) = False Then 

            ' Create a file to write to. 
            Dim createText() As String = {"Hello", "And", "Welcome"}
            File.WriteAllLines(path, createText)
        End If 

        ' This text is always added, making the file longer over time 
        ' if it is not deleted. 
        Dim appendText As String = "This is extra text" + Environment.NewLine
        File.AppendAllText(path, appendText)

        ' Open the file to read from. 
        Dim readText() As String = File.ReadAllLines(path)
        Dim s As String 
        For Each s In readText
            Console.WriteLine(s)
        Next 
    End Sub 
End Class

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

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