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.
Assembly: mscorlib (in mscorlib.dll)
| 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. |
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.
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