Gets or sets a value that specifies the default extension string to use to filter the list of files that are displayed.
Assembly: PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: Not mapped to an xmlns.
The extension string must contain the leading period. For example, set the DefaultExt property to ".txt" to select all text files.
By default, the AddExtension property attempts to determine the extension to filter the displayed file list from the Filter property. If the extension cannot be determined from the Filter property, DefaultExt will be used instead.
The following example shows how to create an OpenFileDialog that contains a default file name and extension type.
' Configure open file dialog box
Dim dlg As New Microsoft.Win32.OpenFileDialog()
dlg.FileName = "Document" ' Default file name
dlg.DefaultExt = ".txt" ' Default file extension
dlg.Filter = "Text documents (.txt)|*.txt" ' Filter files by extension
' Show open file dialog box
Dim result? As Boolean = dlg.ShowDialog()
' Process open file dialog box results
If result = True Then
' Open document
Dim filename As String = dlg.FileName
End If
// Configure open file dialog box
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
dlg.FileName = "Document"; // Default file name
dlg.DefaultExt = ".txt"; // Default file extension
dlg.Filter = "Text documents (.txt)|*.txt"; // Filter files by extension
// Show open file dialog box
Nullable<bool> result = dlg.ShowDialog();
// Process open file dialog box results
if (result == true)
{
// Open document
string filename = dlg.FileName;
}
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.