C# FileChooserDialog.AddNotification方法代码示例

		// This is actually both for "Save As" and saving a file that never
		// been saved before.  Either way, we need to prompt for a filename.
		private bool SaveFileAs (Document document)
		{
			var fcd = new FileChooserDialog (Mono.Unix.Catalog.GetString ("Save Image File"),
									       PintaCore.Chrome.MainWindow,
									       FileChooserAction.Save,
									       Gtk.Stock.Cancel,
									       Gtk.ResponseType.Cancel,
									       Gtk.Stock.Save, Gtk.ResponseType.Ok);

			fcd.DoOverwriteConfirmation = true;
            fcd.SetCurrentFolder (PintaCore.System.GetDialogDirectory ());
			fcd.AlternativeButtonOrder = new int[] { (int)ResponseType.Ok, (int)ResponseType.Cancel };

			bool hasFile = document.HasFile;

			if (hasFile)
				fcd.SetFilename (document.PathAndFileName);

			Dictionary<FileFilter, FormatDescriptor> filetypes = new Dictionary<FileFilter, FormatDescriptor> ();

			// Add all the formats we support to the save dialog
			foreach (var format in PintaCore.System.ImageFormats.Formats) {
				if (!format.IsReadOnly ()) {
					fcd.AddFilter (format.Filter);
					filetypes.Add (format.Filter, format);

					// Set the filter to anything we found
					// We want to ensure that *something* is selected in the filetype
					fcd.Filter = format.Filter;
				}
			}

			// If we already have a format, set it to the default.
			// If not, default to jpeg
			FormatDescriptor format_desc = null;

			if (hasFile)
				format_desc = PintaCore.System.ImageFormats.GetFormatByFile (document.Filename);

			if (format_desc == null) {
				format_desc = PintaCore.System.ImageFormats.GetDefaultSaveFormat ();

				// Gtk doesn't like it if we set the file name to an extension that we don't have
				// a filter for, so we change the extension to our default extension.
				if (hasFile)
					fcd.SetFilename (Path.ChangeExtension (document.PathAndFileName, format_desc.Extensions[0]));
			}

			fcd.Filter = format_desc.Filter;

            fcd.AddNotification("filter", this.OnFilterChanged);

			// Replace GTK's ConfirmOverwrite with our own, for UI consistency
			fcd.ConfirmOverwrite += (eventSender, eventArgs) => {
				if (this.ConfirmOverwrite (fcd, fcd.Filename))
					eventArgs.RetVal = FileChooserConfirmation.AcceptFilename;
				else
					eventArgs.RetVal = FileChooserConfirmation.SelectAgain;
			};

			while (fcd.Run () == (int)Gtk.ResponseType.Ok) {
				FormatDescriptor format = filetypes[fcd.Filter];
				string file = fcd.Filename;

				if (string.IsNullOrEmpty (Path.GetExtension (file))) {
					// No extension; add one from the format descriptor.
					file = string.Format ("{0}.{1}", file, format.Extensions[0]);
					fcd.CurrentName = Path.GetFileName (file);

					// We also need to display an overwrite confirmation message manually,
					// because MessageDialog won't do this for us in this case.
					if (File.Exists (file) && !ConfirmOverwrite (fcd, file))
						continue;
				}

				// Always follow the extension rather than the file type drop down
				// ie: if the user chooses to save a "jpeg" as "foo.png", we are going
				// to assume they just didn't update the dropdown and really want png
				var format_type = PintaCore.System.ImageFormats.GetFormatByFile (file);

				if (format_type != null)
					format = format_type;

				PintaCore.System.LastDialogDirectory = fcd.CurrentFolder;

				// If saving the file failed or was cancelled, let the user select
				// a different file type.
				if (!SaveFile (document, file, format, fcd))
					continue;

				//The user is saving the Document to a new file, so technically it
				//hasn't been saved to its associated file in this session.
				document.HasBeenSavedInSession = false;

				RecentManager.Default.AddFull (fcd.Uri, PintaCore.System.RecentData);
				PintaCore.System.ImageFormats.SetDefaultFormat (Path.GetExtension (file));

				document.HasFile = true;
//.........这里部分代码省略.........