image - Flutter:可以为参数类型 'Image Function(dynamic)'分配哪种类型的参数？

Question

我只是想加载图像。我正在通过网络支持使用Beta channel 。 Flutter 1.19.0-4.3.pre。 Dart 2.9.0
这是我的发布规范:

flutter:
  uses-material-design: true
  assets:
    - assets/

这是我的main.dart;

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Image(image: AssetImage('assets/logo.png')),
          ] < Widget > [
            Text('Find happy, temporary, homes for your pets'),
          ],
        ),
      ),
    );
  }
}
      

我只是从Flutter网站上的文档中复制/粘贴了该内容。我要去哪里错了？

Answer 1

您不必具有two arrays in a single <Widget>[]列类。我可以看到您已经这样做:

<Widget>[
    Image(image: AssetImage('assets/logo.png')),
] < Widget > [
    Text('Find happy, temporary, homes for your pets'),
],

确实是错的。普通Column()接受的是这样的。 [要了解有关列类的更多信息，请单击here]

Column(
  children: <Widget>[
    // You multiple widget goes here not in multiple arrays
    Widget1
    Widget2
    ...
  ]
)

因此，要更正您的代码，您应该执行类似的操作，否则，就assets而言，您已完成了更正

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          // One single array keeps your multiple widgets
          children: <Widget>[
            Image(image: AssetImage('assets/logo.png')),
            Text('Find happy, temporary, homes for your pets'),
          ]
        )
      )
    );
  }
}

让我知道，是否适合您。快乐学习:)