小编ram*_*man的帖子

我不知道为什么控制台框中会出现此错误

控制台消息：

SplashScreenState 通过它的 SingleTickerProviderStateMixin 创建了一个 Ticker，但是在 mixin 上调用 dispose() 时，该 Ticker 仍然处于活动状态。在调用 super.dispose() 之前必须处理 Ticker。AnimationControllers 使用的 Tickers 应该通过调用 AnimationController 本身的 dispose() 来处理。否则，代码会泄漏。违规代码是： Ticker(created by SplashScreenState#dae31(lifecycle state: created))

这是我的启动画面完整代码：

import 'dart:async';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';


class SplashScreen extends StatefulWidget {
  @override
  SplashScreenState createState() => new SplashScreenState();
}

class SplashScreenState extends State<SplashScreen>
    with SingleTickerProviderStateMixin {
  var _visible = true;

  AnimationController animationController;
  Animation<double> animation;

  startTime() async {
    var _duration = new Duration(seconds: 3);
    return new Timer(_duration, navigationPage);
  }

  void navigationPage() {
    Navigator.of(context).pushReplacementNamed(HOME_SCREEN); …

1. 如何在颤振中创建这种类型的仪表板？

2. 这种仪表盘的名称是什么？

我添加了图像以供参考。

这是我的代码。我使用 SystemNavigator.pop 但它说undefined name SystemNavigator

我想要的只是使用 OnTap 退出应用程序

class AppDrawer extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Drawer(
      child: ListView(
        padding: EdgeInsets.zero,
        children: <Widget>[
          _createHeader(),
          _createDrawerItem(
              icon: Icons.home,
              text: 'Home',
              onTap: () => Navigator.of(context).pop()),


          Divider(),

          _createDrawerItem
(icon: Icons.exit_to_app, text: 'Exit app',
onTap: () => SystemNavigator.pop),

          ),
        ],
      ),
    );
  }

SystemNavigator.pop在这种情况下添加的正确方法是什么？如果您知道任何添加方法，请帮助我SystemNavigator.pop

这是我的 Flutter 医生总结：

Running flutter doctor...
Doctor summary (to see all details, run flutter doctor -v):
[?] Flutter (Channel master, v1.10.13-pre.12, on Microsoft Windows [Version 10.0.17134.1006], locale en-IN)
[!] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    X Android license status unknown.
      Try re-installing or updating your Android SDK Manager.
      See https://developer.android.com/studio/#downloads or visit https://flutter.dev/setup/#android-setup for detailed instructions.
[?] Android Studio (version 3.5)
[?] Connected device (1 available)

! Doctor found issues in 1 category.

C:\Users\user>

1. 我已经将我的 …

我尝试在 flutter webview 中使用 GestureRecognizer 来缩小双捏。但它不起作用。如果您有任何解决方案，请帮助我

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';

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

class WebView extends StatefulWidget {
  @override
  _WebViewState createState() => _WebViewState();
}

class _WebViewState extends State<WebView> {
  final Completer<WebViewController> _controller =
      Completer<WebViewController>();

  @override
  Widget build(BuildContext context) {
    return Scaffold(


      body: Builder(builder: (BuildContext context) {
        return WebView(
          key: UniqueKey(),
          gestureRecognizers:
          Set()..add(Factory<TapGestureRecognizer>(() => TapGestureRecognizer(),)),//ZOOM WEBVIEW

          initialUrl:
              '/sf/',

          javascriptMode: JavascriptMode.unrestricted,
          onWebViewCreated: (WebViewController webViewController) {
            _controller.complete(webViewController);
          },
        );
      }),

    );
  }
}

这是代码的重要部分如果您需要完整的代码，请发表评论。