Improve backup functionality and error handling

- (Windows) Fix not selecting the right backup file in explorer
- Fix progress indicator not stopping on WebDAV failure

#188 #364

lib/view/page/backup.dart

@@ -65,14 +65,18 @@ class BackupPage extends StatelessWidget {
             trailing: const Icon(Icons.save),
             onTap: () async {
               final path = await Backup.backup();
+              debugPrint("Backup path: $path");
 
               /// Issue #188
-              final _ = switch (Pfs.type) {
-                Pfs.windows =>
-                  await Process.run('explorer', ['/select,', path]),
-                Pfs.linux => await Process.run('xdg-open', [path]),
-                _ => await Pfs.sharePath(path),
-              };
+              switch (Pfs.type) {
+                case Pfs.windows:
+                    final backslashPath = path.replaceAll('/', '\\');
+                    await Process.run('explorer', ['/select,$backslashPath']);
+                case Pfs.linux:
+                  await Process.run('xdg-open', [path]);
+                default:
+                  await Pfs.sharePath(path);
+              }
             },
           ),
           ListTile(
@@ -263,6 +267,7 @@ class BackupPage extends StatelessWidget {
 
   Future<void> _onTapWebdavDl(BuildContext context) async {
     webdavLoading.value = true;
+    try {
       final files = await Webdav.list();
       if (files.isEmpty) {
         context.showSnackBar(l10n.dirEmpty);
@@ -308,20 +313,34 @@ class BackupPage extends StatelessWidget {
       final dlBak = await Computer.shared.start(Backup.fromJsonString, dlFile);
       await dlBak.restore(force: true);
       webdavLoading.value = false;
+    } catch (e) {
+      context.showSnackBar(e.toString());
+      rethrow;
+    } finally {
+      webdavLoading.value = false;
+    }
   }
 
   Future<void> _onTapWebdavUp(BuildContext context) async {
+    try {
       webdavLoading.value = true;
-    final bakName = '${DateTime.now().ymdhms()}-${Paths.bakName}';
+      final bakName =
+          '${DateTime.now().ymdhms(ymdSep: "-", hmsSep: "-", sep: "-")}-${Paths.bakName}';
       await Backup.backup(bakName);
       final uploadResult = await Webdav.upload(relativePath: bakName);
       if (uploadResult != null) {
         Loggers.app.warning('Upload webdav backup failed: $uploadResult');
+        context.showSnackBar(uploadResult.toString());
       } else {
         Loggers.app.info('Upload webdav backup success');
       }
+    } catch (e) {
+      context.showSnackBar(e.toString());
+      rethrow;
+    } finally {
       webdavLoading.value = false;
     }
+  }
 
   Future<void> _onTapWebdavSetting(BuildContext context) async {
     final urlCtrl = TextEditingController(