FileDialog.DefaultExt Property

Definition

Namespace:

Microsoft.Win32

Assembly:

PresentationFramework.dll

Gets or sets a value that specifies the default extension string to use to filter the list of files that are displayed.

public:
 property System::String ^ DefaultExt { System::String ^ get(); void set(System::String ^ value); };

public string DefaultExt { get; set; }

member this.DefaultExt : string with get, set

Public Property DefaultExt As String

Property Value

String

The default extension string. The default is Empty.

Examples

The following example shows how to create an OpenFileDialog that contains a default file name and extension type.

// 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.Value)
{
    // Open document
    string filename = dlg.FileName;
}

' 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

Remarks

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.