Flutter:放置 Logo 图像后背景变为一半

Question

所以我试图将我的图像标志放在背景上，但我的背景突然被裁剪，出现了一半的黑屏。如图:

我的 main.dart 代码:

import 'package:flutter/material.dart';
import 'login_page.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new LoginPage(),
      theme: new ThemeData(
        primarySwatch: Colors.green
      )
    );
  }
}

我的 login_page.dart 代码:

import 'package:flutter/material.dart';

class LoginPage extends StatefulWidget{
  @override  
  State createState() => new LoginPageState();
}

class LoginPageState extends State<LoginPage>{
  @override 
  Widget build(BuildContext context){
    return new Scaffold(
      backgroundColor: Colors.transparent,
      body: new Container(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Image.asset('assets/arrowPNG.png'),
          ]
        ),
        decoration: BoxDecoration(
          image: DecorationImage(
            image: AssetImage("assets/background.png"),
            fit: BoxFit.cover,
          )
        )
      )
    );
  }
}

它是在放置图像标志“Image.asset('assets/arrowPNG.png'),”之后发生的。我该如何解决这个问题？

Answer 1

试试下面的代码

class LoginPageState extends State<LoginPage>{
    @override
      Widget build(BuildContext context){
        return new Scaffold(
            backgroundColor: Colors.transparent,
            body: new Container(
              width: MediaQuery.of(context).size.width,
                child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      Image.asset('images/a_dot_ham.png'),
                    ]
                ),
                decoration: BoxDecoration(
                    image: DecorationImage(
                      image: AssetImage("images/background.jpg"),
                      fit: BoxFit.cover,
                    )
                )
            )
        );
    }

当您将以下行添加到容器时，问题将得到解决

width: MediaQuery.of(context).size.width

这是我的结果