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)
Parameters
- file
- Type: System.String
Name and path of the file to read.
| 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 |
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.
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
