FileSystem.WriteAllText Method

Definition

Namespace:

Microsoft.VisualBasic.FileIO

Assembly:

Microsoft.VisualBasic.Core.dll

Writes text to a file.

Overloads

WriteAllText(String, String, Boolean)	Writes text to a file.
WriteAllText(String, String, Boolean, Encoding)	Writes text to a file.

WriteAllText(String, String, Boolean)

Source:

FileSystem.vb

Writes text to a file.

public:
 static void WriteAllText(System::String ^ file, System::String ^ text, bool append);

public static void WriteAllText (string file, string text, bool append);

static member WriteAllText : string * string * bool -> unit

Public Shared Sub WriteAllText (file As String, text As String, append As Boolean)

Parameters

file

String

File to be written to.

text

String

Text to be written to file.

append

Boolean

True to append to the contents of the file; False to overwrite the contents of the file.

Exceptions

ArgumentException

The path is not valid for one of the following reasons: it is a zero-length string; it contains only white space; it contains invalid characters; or it is a device path (starts with \\.\); it ends with a trailing slash.

ArgumentNullException

file is Nothing.

FileNotFoundException

The file does not exist.

IOException

The file is in use by another process, or an I/O error occurs.

PathTooLongException

The path exceeds the system-defined maximum length.

NotSupportedException

A file or directory name in the path contains a colon (:) or is in an invalid format.

OutOfMemoryException

There is not enough memory to write the string to buffer.

SecurityException

The user lacks necessary permissions to view the path.

Examples

This example writes the line "This is new text to be added." to the file Test.txt, overwriting any existing text in the file.

My.Computer.FileSystem.WriteAllText("C:\TestFolder1\test.txt",
"This is new text to be added.", False)

This example writes the names of the files in the Documents and Settings folder to FileList.txt, inserting a carriage return between each for better readability.

For Each foundFile In
        My.Computer.FileSystem.GetFiles("C:\Documents and Settings")
    foundFile = foundFile & vbCrLf
    My.Computer.FileSystem.WriteAllText(
        "C:\Documents and Settings\FileList.txt", foundFile, True)
Next

Remarks

The UTF-8 encoding is used to write to the file. To specify a different encoding, use a different overload of the WriteAllText method.

If the specified file does not exist, it is created.

If the specified encoding does not match the existing encoding of the file, the specified coding is ignored.

Note

The WriteAllText method opens a file, writes to it, and then closes it. Code that uses the WriteAllText method is simpler than code that uses a StreamWriter object. However, if you are adding strings to a file by using a loop, a StreamWriter object can provide better performance because you only have to open and close the file one time. For more information, see the OpenTextFileWriter method.

The following table lists examples of tasks involving the My.Computer.FileSystem.WriteAllText method.

To	See
Write text to a file	How to: Write Text to Files in Visual Basic
Append text to a file	How to: Append to Text Files in Visual Basic

See also

• Encoding
• WriteAllText

WriteAllText(String, String, Boolean, Encoding)

Source:

FileSystem.vb

Writes text to a file.

public:
 static void WriteAllText(System::String ^ file, System::String ^ text, bool append, System::Text::Encoding ^ encoding);

public static void WriteAllText (string file, string text, bool append, System.Text.Encoding encoding);

static member WriteAllText : string * string * bool * System.Text.Encoding -> unit

Public Shared Sub WriteAllText (file As String, text As String, append As Boolean, encoding As Encoding)

Parameters

file

String

File to be written to.

text

String

Text to be written to file.

append

Boolean

True to append to the contents of the file; False to overwrite the contents of the file.

encoding

Encoding

What encoding to use when writing to file.

Exceptions

ArgumentException

The path is not valid for one of the following reasons: it is a zero-length string; it contains only white space; it contains invalid characters; or it is a device path (starts with \\.\); it ends with a trailing slash.

ArgumentNullException

file is Nothing.

FileNotFoundException

The file does not exist.

IOException

The file is in use by another process, or an I/O error occurs.

PathTooLongException

The path exceeds the system-defined maximum length.

NotSupportedException

A file or directory name in the path contains a colon (:) or is in an invalid format.

OutOfMemoryException

There is not enough memory to write the string to buffer.

SecurityException

The user lacks necessary permissions to view the path.

Examples

This example writes the line "This is new text to be added." to the file Test.txt, overwriting any existing text in the file.

My.Computer.FileSystem.WriteAllText("C:\TestFolder1\test.txt",
"This is new text to be added.", False)

This example writes the names of the files in the Documents and Settings folder to FileList.txt, inserting a carriage return between each for better readability.

For Each foundFile In
        My.Computer.FileSystem.GetFiles("C:\Documents and Settings")
    foundFile = foundFile & vbCrLf
    My.Computer.FileSystem.WriteAllText(
        "C:\Documents and Settings\FileList.txt", foundFile, True)
Next

Remarks

If the specified file does not exist, it is created.

If the specified encoding does not match the existing encoding of the file, the specified coding is ignored.

Note

The WriteAllText method opens a file, writes to it, and then closes it. Code that uses the WriteAllText method is simpler than code that uses a StreamWriter object. However, if you are adding strings to a file by using a loop, a StreamWriter object can provide better performance because you only have to open and close the file one time. For more information, see the OpenTextFileWriter method.

The following table lists examples of tasks involving the My.Computer.FileSystem.WriteAllText method.

To	See
Write text to a file	How to: Write Text to Files in Visual Basic
Append text to a file	How to: Append to Text Files in Visual Basic

See also

• Encoding