FileSystem.ReadAllText Method (String)

 

Returns the contents of a text file as a String.

Namespace:   Microsoft.VisualBasic.FileIO
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

public static string ReadAllText(
	string file
)

Parameters

file
Type: System.String

Name and path of the file to read.

Return Value

Type: System.String

String containing the contents of the file.

Exception Condition
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.

The ReadAllText method of the My.Computer.FileSystem object allows you to read from a text file. The contents of the file are returned as a string.

The file encoding can be specified if the contents of the file are in an encoding such as ASCII or UTF-8. If you are reading from a file with extended characters, you need to specify the file encoding using another overload of the ReadAllText method.

Do not make decisions about the contents of the file based on the name of the file. For example, the file Form1.vb may not be a Visual Basic source file. Verify all inputs before using the data in your application.

The following table lists an example of a task involving the My.Computer.FileSystem.ReadAllText method.

To

See

Read from a text file

How to: Read From Text Files in Visual Basic

This example reads the contents of Test.txt into a string and then displays it in a message box.

Dim reader = My.Computer.FileSystem.ReadAllText("C:\test.txt")
MsgBox(reader)

This example reads the contents of the ASCII file Test.txt into a string and then displays it in a message box.

Dim reader = My.Computer.FileSystem.ReadAllText("C:\test.txt",
   System.Text.Encoding.ASCII)
MsgBox(reader)

FileIOPermission

Controls the ability to access files and folders. Associated enumeration: Unrestricted.

.NET Framework
Available since 2.0
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