FileInfo.Open Method (FileMode)
.NET Framework (current version)
Opens a file in the specified mode.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- mode
-
Type:
System.IO.FileMode
A FileMode constant specifying the mode (for example, Open or Append) in which to open the file.
Return Value
Type: System.IO.FileStreamA file opened in the specified mode, with read/write access and unshared.
| Exception | Condition |
|---|---|
| FileNotFoundException | The file is not found. |
| UnauthorizedAccessException | The file is read-only or is a directory. |
| DirectoryNotFoundException | The specified path is invalid, such as being on an unmapped drive. |
| IOException | The file is already open. |
The following example opens a file, adds some information to the file, and reads the file.
Imports System Imports System.IO Imports System.Text Public Class Test Public Shared Sub Main() Dim path As String = "c:\temp\MyTest.txt" Dim fi As FileInfo = New FileInfo(path) Dim fs As FileStream ' Delete the file if it exists. If fi.Exists = False Then 'Create the file. fs = fi.Create() 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 = fi.Open(FileMode.Open) 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 'This code produces output similar to the following; 'results may vary based on the computer/file structure/etc.: ' 'This is some text in the file. ' ' ' ' ' ' ' ' ' ' ' '
FileIOPermission
for writing to and reading from files. Associated enumerations: FileIOPermissionAccess.Write and FileIOPermissionAccess.Read
Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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