flutter - 如何修复这个颤振错误'package：flutter/scr/painting/image_resolution.dart''assetName！= null'不正确

Question

我还是 Flutter 的新手。我的代码一切都很好，但是每当我尝试启动该应用程序时，它总是在屏幕上出现这种错误。所以这是来自 main.dart 错误：“package:flutter/src/painting/image_resolution.dart”断言失败：fline 134 pos 15assetName != null' is not true

import 'package:autibuddyapp/Notification.dart';
import 'package:autibuddyapp/profile.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:curved_navigation_bar/curved_navigation_bar.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:autibuddyapp/griddashboard.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: MyHomePage(),
    );
  }
}
class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage>{
  final pages = [Notify(),  MyHomePage() ,Profile(),] ;
  var mypages = 1;


  @override
  Widget build(BuildContext context) {

    String greeting() {
    var hour = DateTime.now().hour;

    if (hour < 12) {
      return 'Good Morning Buddy';
    } if (hour < 15) {
      return 'Good Aftenoon Buddy';
    }  if (hour < 19) {
      return 'Good Evening Buddy';
    }
      return
        'Good Night Buddy, time to get some sleep';
    }

    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.purple,
        title: Text("Auti Buddy", style: TextStyle(
            color: Colors.black
        ),),
      ),
      body: SingleChildScrollView(
          child: Container(
              height: MediaQuery.of(context).size.height,
               width: MediaQuery.of(context).size.width,


              decoration: BoxDecoration(
              image: DecorationImage(
              image: AssetImage("assets/buddy.png"),fit: BoxFit.fill),
              ),



                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                     Text(
              'Good Morning Buddy',
              semanticsLabel: greeting(),
              style: TextStyle(
                  fontSize: 30.0,
                  color: Colors.black,
              ),
            ),


                   SizedBox(
                     height: 60,
                   ),


                    Padding(
                     padding: EdgeInsets.only(left: 16, right: 16),

                      child: Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: <Widget>[
                          Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                            children: <Widget>[
                               Text(
                              "Welcome!",
                             style: GoogleFonts.cairo(
                            textStyle: TextStyle(
                                color: Colors.black54,
                                fontSize: 26,
                                fontWeight: FontWeight.bold)),
                      ),
                      SizedBox(
                        height: 4,
                      ),
                      Text(
                        "Home",
                        style: GoogleFonts.openSans(
                            textStyle: TextStyle(
                                color: Color(0xffa29aac),
                                fontSize: 16,
                                fontWeight: FontWeight.w600)),
                      ),
                    ],
                  ),
                ],
              ),
            ),
            SizedBox(
              height: 40,
            ),

                    GridDashboard()

          ],
        ),
      ),

      ),
           bottomNavigationBar: CurvedNavigationBar(

             index : 1,
             color: Colors.purple,
             backgroundColor: Colors.white,
             buttonBackgroundColor: Colors.purpleAccent,
             height: 50,
             animationDuration: Duration (
             milliseconds: 200
              ),
              animationCurve: Curves.bounceInOut,
              onTap: (index){
              setState(() {
               mypages = index;
              });
             },

               items:<Widget>[
                  Icon(Icons.notifications_none,size: 20, color: Colors.black,),
                  Icon(Icons.home,size: 20, color: Colors.black),
                  Icon(Icons.account_circle,size: 20, color: Colors.black,),
                ],

           ),




    );

标签： flutterdart