DiagramControl.ShowingOpenDialog Event
Fires before showing an ‘Open File’ dialog, and allows it to be customized or replaced.
Namespace: DevExpress.XtraDiagram
Assembly: DevExpress.XtraDiagram.v24.1.dll
NuGet Package: DevExpress.Win.Diagram
Declaration
[DiagramCategory(DiagramCategory.DiagramDocument)]
public event EventHandler<DiagramShowingOpenDialogEventArgs> ShowingOpenDialogEvent Data
The ShowingOpenDialog event's data class is DiagramShowingOpenDialogEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Cancel | Gets or sets a value indicating whether the event should be canceled. Inherited from CancelEventArgs. |
| DocumentSourceToOpen | Gets or sets the object from which to load the diagram skipping the dialog window. This object can be a full file path, Uri object, stream or array of bytes. |
| Filter | Gets or sets the string that determines the file filtering options that appear in the dialog. |
| InitialDirectory | Gets or sets the path to the directory displayed by the dialog. |
| Title | Gets or sets the title of the dialog. |
Remarks
The Diagram Control’s Ribbon menu provides the ‘Open’ action that allows an end-user to load a diagram from an external file. The ShowingOpenDialog event fires when the ‘Open File’ dialog is about to be invoked. You can handle it to change the dialog options or prevent the dialog from being displayed. For instance, you can set the Cancel event parameter to true to suppress the default dialog and then show a custom diagram load dialog.
You can also use the following event parameters:
DocumentSourceToOpen - allows you to specify the object from which to automatically load the diagram. This object can be a file full path, Uri object, stream and array of bytes. If this event parameter is set, a diagram will be automatically loaded from the specified source; the default ‘Open File’ dialog will not be invoked.
You may encounter exceptions when loading/saving a diagram (e.g., when trying to load a diagram from a file that does not exist, or from an empty stream). To handle or suppress these exceptions, use the DiagramControl.ExceptionMessage event.
- Filter - allows you to specify a filter string that specifies the file types and descriptions to display in the ‘Open File’ dialog. This value will be used to initialize the System.Windows.Forms.FileDialog.Filter property.
- InitialDirectory - allows you to specify the initial directory displayed by the ‘Open File’ dialog.
- Title - allows you to specify the ‘Open File’ dialog title.