FileMode Enumeration
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Specifies how the operating system should open a file.
Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Syntax
Public Enumeration FileMode
public enum FileMode
Members
| Member name | Description | |
|---|---|---|
| Append | Opens the file if it exists and seeks to the end of the file, or creates a new file. Append can only be used in conjunction with Write. Attempting to seek to a position before the end of the file will throw an IOException and any attempt to read fails and throws an NotSupportedException. | |
| Create | Specifies that the operating system should create a new file. If the file already exists, it will be overwritten. Create is equivalent to requesting that if the file does not exist, use CreateNew; otherwise, use Truncate. | |
| CreateNew | Specifies that the operating system should create a new file. | |
| Open | Specifies that the operating system should open an existing file. The ability to open the file is dependent on the value specified by FileAccess. A System.IO..::.FileNotFoundException is thrown if the file does not exist. | |
| OpenOrCreate | Specifies that the operating system should open a file if it exists; otherwise, a new file should be created. | |
| Truncate | Specifies that the operating system should open an existing file. Once opened, the file should be truncated so that its size is zero bytes. |
Remarks
Specify a FileMode parameter IsolatedStorageFileStream constructors.
FileMode parameters control whether a file is overwritten, created, opened, or some combination thereof. Use Open to open an existing file. To append to a file, use Append. To truncate a file or create a file if it doesn't exist, use Create.
Examples
The following example opens an existing file. This example is part of a larger example provided for the IsolatedStorageFile class.
' Write to an existing file: MyApp1\SubDir1\MyApp1A.txt
' Determine if the file exists before writing to it.
Dim filePath As String = Path.Combine(subdirectory1, "MyApp1A.txt")
If store.FileExists(filePath) Then
Try
Using sw As StreamWriter = _
New StreamWriter(store.OpenFile(filePath, FileMode.Open, FileAccess.Write))
sw.WriteLine("To do list:")
sw.WriteLine("1. Buy supplies.")
End Using
Catch ex As IsolatedStorageException
sb.AppendLine(ex.Message)
End Try
Else
sb.AppendLine((filePath + "does not exist"))
End If
// Write to an existing file: MyApp1\SubDir1\MyApp1A.txt
// Determine if the file exists before writing to it.
string filePath = Path.Combine(subdirectory1, "MyApp1A.txt");
if (store.FileExists(filePath))
{
try
{
using (StreamWriter sw =
new StreamWriter(store.OpenFile(filePath,
FileMode.Open, FileAccess.Write)))
{
sw.WriteLine("To do list:");
sw.WriteLine("1. Buy supplies.");
}
}
catch (IsolatedStorageException ex)
{
sb.AppendLine(ex.Message);
}
}
Version Information
Windows Phone OS
Supported in: 8.1, 8.0, 7.1, 7.0
Platforms
Windows Phone