结构初始化

lib/core/provider_base.dart

@@ -0,0 +1,36 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+
+class ProviderBase with ChangeNotifier {
+  void setState(void Function() callback) {
+    callback();
+    notifyListeners();
+  }
+}
+
+enum ProviderState {
+  idle,
+  busy,
+}
+
+class BusyProvider extends ProviderBase {
+  bool _isBusy = false;
+  bool get isBusy => _isBusy;
+
+  setBusyState([bool isBusy = true]) {
+    _isBusy = isBusy;
+    notifyListeners();
+  }
+
+  FutureOr<T> busyRun<T>(FutureOr<T> Function() func) async {
+    setBusyState(true);
+    try {
+      return await Future.sync(func);
+    } catch (e) {
+      rethrow;
+    } finally {
+      setBusyState(false);
+    }
+  }
+}