Gets or sets the default file name extension applied to files that are saved with the SaveFileDialog.
Assembly: System.Windows (in System.Windows.dll)
The default file name extension is applied when the selected filter does not specify an extension (or the Filter property is not set) and the user does not specify an extension. For example, if the property is set to .my, the selected item in the Save as type drop-down list has a filter string set to All Files|*.*, and a file name without a extension is specified in the File name box, the file is saved with the .my extension.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.