Question

我有一个FloatingActionButton可以工作多个的示例，但是我不知道如何在onPressed上添加它。我发现以下主题的形式： https://stackoverflow.com/a/46480722/14451514

在示例中，我需要知道三个图标onPressed它是如何做到的？


import 'package:flutter/material.dart';
import 'dart:math' as math;

void main() {
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  State createState() => new MyHomePageState();
}

class MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
  AnimationController _controller;

  static const List<IconData> icons = const [ Icons.sms, Icons.mail, Icons.phone ];

  @override
  void initState() {
    _controller = new AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 500),
    );
  }

  Widget build(BuildContext context) {
    Color backgroundColor = Theme.of(context).cardColor;
    Color foregroundColor = Theme.of(context).accentColor;
    return new Scaffold(
      appBar: new AppBar(title: new Text('Speed Dial Example')),
      floatingActionButton: new Column(
        mainAxisSize: MainAxisSize.min,
        children: new List.generate(icons.length, (int index) {
          Widget child = new Container(
            height: 70.0,
            width: 56.0,
            alignment: FractionalOffset.topCenter,
            child: new ScaleTransition(
              scale: new CurvedAnimation(
                parent: _controller,
                curve: new Interval(
                    0.0,
                    1.0 - index / icons.length / 2.0,
                    curve: Curves.easeOut
                ),
              ),
              child: new FloatingActionButton(
                heroTag: null,
                backgroundColor: backgroundColor,
                mini: true,
                child: new Icon(icons[index], color: foregroundColor),
                onPressed: () {},
              ),
            ),
          );
          return child;
        }).toList()..add(
          new FloatingActionButton(
            heroTag: null,
            child: new AnimatedBuilder(
              animation: _controller,
              builder: (BuildContext context, Widget child) {
                return new Transform(
                  transform: new Matrix4.rotationZ(_controller.value * 0.5 * math.pi),
                  alignment: FractionalOffset.center,
                  child: new Icon(_controller.isDismissed ? Icons.share : Icons.close),
                );
              },
            ),
            onPressed: () {
              if (_controller.isDismissed) {
                _controller.forward();
              } else {
                _controller.reverse();
              }
            },
          ),
        ),
      ),
    );
  }
}

如果有人知道该问题的解决方案，请帮助我

Answer 1

我建议您添加一个FAB Onpress按钮，使用此github程序。 Speed Dail Floating Action Bar

https://github.com/tiagojencmartins/unicornspeeddial

Answer 2

您需要将IconData列表扩展到包含Function的模型。看起来像这样：

     class NewModel {
      IconData iconData;
      Function func;          
     }

然后：

     static const List<NewModel> iconsWithFunc = 
                    [ 
                         /* Your Items with OnPressed Functions */      
                    ];

之后，您可以轻松使用它：

       child: new FloatingActionButton(
            heroTag: null,
            backgroundColor: backgroundColor,
            mini: true,
            child: new Icon(iconsWithFunc[index].iconData, color: foregroundColor),
            // Use it in here.
            onPressed: iconsWithFunc[index].func,
          ),

Answer 3

函数列表（数组）可以在这里为您提供帮助，您拥有当前项目的索引，只需按索引从列表中获取函数，然后将其称为onPress即可。


import 'package:flutter/material.dart';
import 'dart:math' as math;

void main() {
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  State createState() => new MyHomePageState();
}

class MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
  AnimationController _controller;

  static const List<IconData> icons = const [
    Icons.sms,
    Icons.mail,
    Icons.phone
  ];

  static method1() {
    print('method 1');
  }

  static method2() {
    print('method 2');
  }

  static method3() {
    print('method 3');
  }

  List<Function> methods = [method1, method2, method3];

  @override
  void initState() {
    _controller = new AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 500),
    );
  }

  Widget build(BuildContext context) {
    Color backgroundColor = Theme.of(context).cardColor;
    Color foregroundColor = Theme.of(context).accentColor;
    return new Scaffold(
      appBar: new AppBar(title: new Text('Speed Dial Example')),
      floatingActionButton: new Column(
        mainAxisSize: MainAxisSize.min,
        children: new List.generate(icons.length, (int index) {
          Widget child = new Container(
            height: 70.0,
            width: 56.0,
            alignment: FractionalOffset.topCenter,
            child: new ScaleTransition(
              scale: new CurvedAnimation(
                parent: _controller,
                curve: new Interval(0.0, 1.0 - index / icons.length / 2.0,
                    curve: Curves.easeOut),
              ),
              child: new FloatingActionButton(
                heroTag: null,
                backgroundColor: backgroundColor,
                mini: true,
                child: new Icon(icons[index], color: foregroundColor),
                onPressed: () {
                  methods[index]();
                },
              ),
            ),
          );
          return child;
        }).toList()
          ..add(
            new FloatingActionButton(
              heroTag: null,
              child: new AnimatedBuilder(
                animation: _controller,
                builder: (BuildContext context, Widget child) {
                  return new Transform(
                    transform: new Matrix4.rotationZ(
                        _controller.value * 0.5 * math.pi),
                    alignment: FractionalOffset.center,
                    child: new Icon(
                        _controller.isDismissed ? Icons.share : Icons.close),
                  );
                },
              ),
              onPressed: () {
                if (_controller.isDismissed) {
                  _controller.forward();
                } else {
                  _controller.reverse();
                }
              },
            ),
          ),
      ),
    );
  }
}

尝试一下

如何在颤振中将onPressed添加到多个FloatingActionButton

3 个答案: