Question

这是我要实现的目标： Image that I want

我已经考虑过在MouseRegion小部件中使用onHover，并试图查看此代码是否在正文部分中起作用。
我在主体部分看到了此功能后，将要在脚手架的AppBar中实现此功能，但我做不到。有人知道正确的方法吗？

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

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

class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: Center(
          child: MyStatefulWidget(),
        ),
      ),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  showMenus(BuildContext context) async {
    await showMenu(
      context: context,
      position: RelativeRect.fromLTRB(100, 100, 100, 100),
      items: [
        PopupMenuItem(
          child: Text("View"),
        ),
        PopupMenuItem(
          child: Text("Edit"),
        ),
        PopupMenuItem(
          child: Text("Delete"),
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return ConstrainedBox(
      constraints: BoxConstraints.tight(Size(300.0, 200.0)),
      child: MouseRegion(
        onHover: showMenus(context),
        child: Container(
          color: Colors.lightBlueAccent,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text('You have entered or exited this box this many times:'),
            ],
          ),
        ),
      ),
    );
  }
}

Answer 1

您唯一的问题是错误地调用了该方法。在您的MouseRegion onHover上，在调用该方法之前应该有一个() =>：

// the onHover event gives you an event object
onHover: (event) => showMenus(context),

当鼠标悬停在AppBar中时，如何显示完整菜单？

1 个答案: