Opens an existing file for reading.
Assembly: mscorlib (in mscorlib.dll)
path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by InvalidPathChars.
path is Nothing.
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.
The specified path is invalid, (for example, it is on an unmapped drive).
path specified a directory.
The caller does not have the required permission.
The file specified in path was not found.
path is in an invalid format.
The path parameter is permitted to specify relative or absolute path information. Relative path information is interpreted as relative to the current working directory. To obtain the current working directory, see GetCurrentDirectory.
For a list of common I/O tasks, see Common I/O Tasks.
The following example opens a file for reading.
Imports System Imports System.IO Imports System.Text Public Class Test Public Shared Sub Main() Dim path As String = "c:\temp\MyTest.txt" Dim fs As FileStream ' Delete the file if it exists. If File.Exists(path) = False Then ' Create the file. fs = File.Create(path) Dim info As Byte() = New UTF8Encoding(True).GetBytes("This is some text in the file.") ' Add some information to the file. fs.Write(info, 0, info.Length) fs.Close() End If ' Open the stream and read it back. fs = File.OpenRead(path) Dim b(1024) As Byte Dim temp As UTF8Encoding = New UTF8Encoding(True) Do While fs.Read(b, 0, b.Length) > 0 Console.WriteLine(temp.GetString(b)) Loop fs.Close() End Sub End Class
Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, 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.