全局loading

readme.md

Create by https://gist.github.com/CaiJingLong/a299d15b92edc2d09a8a06cf6dd5a1b0

main.dart

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: HomePage(),
      navigatorKey: navigatorKey,
    );
  }
}

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Container(),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          showLoadingDialog();
        },
        child: Text('.'),
      ),
    );
  }
}

GlobalKey<NavigatorState> navigatorKey = GlobalKey();

NavigatorState get navigator => navigatorKey.currentState;

Future<T> showLoadingDialog<T>() {
  return navigator.push<T>(
    MyDialogRoute(
      pageBuilder: (BuildContext context, Animation<double> animation,
          Animation<double> secondaryAnimation) {
        return WillPopScope(
          onWillPop: () async {
            return false;
          },
          child: Center(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: <Widget>[
                Center(
                  child: SizedBox(
                    width: 40,
                    height: 40,
                    child: CircularProgressIndicator(),
                  ),
                ),
                RaisedButton(
                  child: Text('close dialog'),
                  onPressed: () {
                    Navigator.pop(context);
                  },
                ),
              ],
            ),
          ),
        );
      },
      barrierDismissible: false,
    ),
  );
}

class MyDialogRoute<T> extends PopupRoute<T> {
  MyDialogRoute({
    @required RoutePageBuilder pageBuilder,
    bool barrierDismissible = true,
    String barrierLabel,
    Color barrierColor = const Color(0x80000000),
    Duration transitionDuration = const Duration(milliseconds: 200),
    RouteTransitionsBuilder transitionBuilder,
    RouteSettings settings,
  })  : assert(barrierDismissible != null),
        _pageBuilder = pageBuilder,
        _barrierDismissible = barrierDismissible,
        _barrierLabel = barrierLabel,
        _barrierColor = barrierColor,
        _transitionDuration = transitionDuration,
        _transitionBuilder = transitionBuilder,
        super(settings: settings);

  final RoutePageBuilder _pageBuilder;

  @override
  bool get barrierDismissible => _barrierDismissible;
  final bool _barrierDismissible;

  @override
  String get barrierLabel => _barrierLabel;
  final String _barrierLabel;

  @override
  Color get barrierColor => _barrierColor;
  final Color _barrierColor;

  @override
  Duration get transitionDuration => _transitionDuration;
  final Duration _transitionDuration;

  final RouteTransitionsBuilder _transitionBuilder;

  @override
  Widget buildPage(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation) {
    return Semantics(
      child: _pageBuilder(context, animation, secondaryAnimation),
      scopesRoute: true,
      explicitChildNodes: true,
    );
  }

  @override
  Widget buildTransitions(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation, Widget child) {
    if (_transitionBuilder == null) {
      return FadeTransition(
          opacity: CurvedAnimation(
            parent: animation,
            curve: Curves.linear,
          ),
          child: child);
    } // Some default transition
    return _transitionBuilder(context, animation, secondaryAnimation, child);
  }
}