I/where 如何将自定义动画浮动操作按钮置于主要 page/content 之上？扑

Question

我遵循了一些关于创建自定义浮动操作按钮的教程，并成功地重新创建了它并根据我的喜好进行了自定义。但是，我遇到了初学者问题，而我不知道如何 to/where 开始构建内容的主体。

更具体地说，我想构建一个视频提要（如 instagram/youtube 样式），但将 FAB（浮动操作按钮）用作此菜单和其他一些菜单屏幕。

如何在代码中I/where开始构建我的内容主体？

请在下面找到我当前的自定义操作按钮和动画代码。谢谢你的时间。

import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/painting.dart';
import 'constants.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Mandaboo',
      theme: ThemeData(

      ),
      home: MyHomePage(
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with SingleTickerProviderStateMixin {

  AnimationController animationController;
  Animation degOneTranslationAnimation,degTwoTranslationAnimation,degThreeTranslationAnimation, degFourTranslationAnimation;
  Animation rotationAnimation;


  double getRadiansFromDegree(double degree) {
    double unitRadian = 57.295779513;
    return degree / unitRadian;
  }

  @override
  void initState() {
    animationController = AnimationController(vsync: this,duration: Duration(milliseconds: 250));
    degOneTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 1.2), weight: 75.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 1.2,end: 1.0), weight: 25.0),
    ]).animate(animationController);
    degTwoTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 1.4), weight: 55.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 1.4,end: 1.0), weight: 45.0),
    ]).animate(animationController);
    degThreeTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 1.75), weight: 35.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 1.75,end: 1.0), weight: 65.0),
    ]).animate(animationController);
    degFourTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 2.10), weight: 15.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 2.10,end: 1.0), weight: 85.0),
    ]).animate(animationController);
    rotationAnimation = Tween<double>(begin: 180.0,end: 0.0).animate(CurvedAnimation(parent: animationController
        , curve: Curves.easeOut));
    super.initState();
    animationController.addListener((){
      setState(() {

      });
    });
  }


  @override
  Widget build(BuildContext context) {
    Size size = MediaQuery.of(context).size;
    return Container(
      child: Scaffold(
          body: Container(
            width: size.width,
            height: size.height,
            child: Stack(
              children: <Widget>[
                Positioned(
                    right: 30,
                    bottom: 30,
                    child: Stack(
                      alignment: Alignment.bottomRight,
                      children: <Widget>[
                        IgnorePointer(
                          child: Container(
                            color: Colors.white.withOpacity(0.0), // comment or change to transparent color
                            height: 150.0,
                            width: 150.0,
                          ),
                        ),
                        Transform.translate(
                          offset: Offset.fromDirection(getRadiansFromDegree(270),degOneTranslationAnimation.value * 100),
                          child: Transform(
                            transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degOneTranslationAnimation.value),
                            alignment: Alignment.center,
                            child: CircularButton(
                              color: Colors.red,
                              width: 40,
                              height: 40,
                              icon: Icon(
                                Icons.add,
                                color: Colors.white,
                              ),
                              onClick: (){
                                print('First Button');
                              },
                            ),
                          ),
                        ),
                        Transform.translate(
                          offset: Offset.fromDirection(getRadiansFromDegree(240),degTwoTranslationAnimation.value * 100),
                          child: Transform(
                            transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degTwoTranslationAnimation.value),
                            alignment: Alignment.center,
                            child: CircularButton(
                              color: Colors.black54,
                              width: 40,
                              height: 40,
                              icon: Icon(
                                Icons.shop_two,
                                color: Colors.white,
                              ),
                              onClick: (){
                                print('Second button');
                              },
                            ),
                          ),
                        ),
                        Transform.translate(
                          offset: Offset.fromDirection(getRadiansFromDegree(210),degThreeTranslationAnimation.value * 100),
                          child: Transform(
                            transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degThreeTranslationAnimation.value),
                            alignment: Alignment.center,
                            child: CircularButton(
                              color: Colors.black54,
                              width: 40,
                              height: 40,
                              icon: Icon(
                                Icons.equalizer,
                                color: Colors.white,
                              ),
                              onClick: (){
                                print('Third Button');
                              },
                            ),
                          ),
                        ),
                        Transform.translate(
                          offset: Offset.fromDirection(getRadiansFromDegree(180),degFourTranslationAnimation.value * 100),
                          child: Transform(
                            transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degFourTranslationAnimation.value),
                            alignment: Alignment.center,
                            child: CircularButton(
                              color: Colors.black54,
                              width: 40,
                              height: 40,
                              icon: Icon(
                                Icons.settings,
                                color: Colors.white,
                              ),
                              onClick: (){
                                print('Fourth Button');
                              },
                            ),
                          ),
                        ),
                        Transform(
                          transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value)),
                          alignment: Alignment.center,
                          child: CircularButton(
                            color: Colors.red,
                            width: 60,
                            height: 60,
                            icon: Icon(
                              Icons.menu,
                              color: Colors.white,
                            ),
                            onClick: (){
                              if (animationController.isCompleted) {
                                animationController.reverse();
                              } else {
                                animationController.forward();
                              }
                            },
                          ),
                        )

                      ],
                    ))
              ],
            ),
          ),

      ),
    );
  }
}


class CircularButton extends StatelessWidget {

  final double width;
  final double height;
  final Color color;
  final Icon icon;
  final Function onClick;

  CircularButton({this.color, this.width, this.height, this.icon, this.onClick});


  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(color: color,shape: BoxShape.circle),
      width: width,
      height: height,
      child: IconButton(icon: icon,enableFeedback: true, onPressed: onClick),
    );
  }
}

p.s - 我知道对此可能有一个非常简单的答案，但我现在还不知道。 p.p.s - 我对此进行了认真的搜索，但找不到答案，因此提出了这个问题。

Answer 1

假设这是您的小部件树创建主要内容 body 通过 flutter codelabs

一些建议

Material 库中的 Scaffold 小部件提供了一个默认应用栏、一个标题和一个 body 属性用于保存主屏幕的小部件树。小部件子树可能非常复杂。
小部件的主要工作是提供一种构建方法，该方法描述如何根据其他 lower-level 小部件显示小部件。

然后添加自定义浮动按钮，您需要做的就是

...
Scaffold(
body: Center(..
floatingActionButton:MyCustomFaB(),

Answer 2

您可以复制粘贴运行下面的完整代码
您可以将您的自定义 Floating Action Button 移动到 Scaffold 的 floatingActionButton 并将您的主要内容放在 body

return Scaffold(
      appBar: AppBar(
        title: const Text('Test page'),
      ),
      body: ListView.separated(
        padding: const EdgeInsets.all(8),
        itemCount: 50,
        itemBuilder: (BuildContext context, int index) {
          return Container(
            height: 50,
            color: Colors.blue,
            child: Center(child: Text('Entry ${index}')),
          );
        },
        separatorBuilder: (BuildContext context, int index) => const Divider(),
      ),
      floatingActionButton: Stack(
        children: <Widget>[
          Positioned(

工作演示

完整代码

import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/painting.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Mandaboo',
      theme: ThemeData(),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage>
    with SingleTickerProviderStateMixin {
  AnimationController animationController;
  Animation degOneTranslationAnimation,
      degTwoTranslationAnimation,
      degThreeTranslationAnimation,
      degFourTranslationAnimation;
  Animation rotationAnimation;

  double getRadiansFromDegree(double degree) {
    double unitRadian = 57.295779513;
    return degree / unitRadian;
  }

  @override
  void initState() {
    animationController =
        AnimationController(vsync: this, duration: Duration(milliseconds: 250));
    degOneTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 0.0, end: 1.2), weight: 75.0),
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 1.2, end: 1.0), weight: 25.0),
    ]).animate(animationController);
    degTwoTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 0.0, end: 1.4), weight: 55.0),
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 1.4, end: 1.0), weight: 45.0),
    ]).animate(animationController);
    degThreeTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 0.0, end: 1.75), weight: 35.0),
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 1.75, end: 1.0), weight: 65.0),
    ]).animate(animationController);
    degFourTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 0.0, end: 2.10), weight: 15.0),
      TweenSequenceItem<double>(
          tween: Tween<double>(begin: 2.10, end: 1.0), weight: 85.0),
    ]).animate(animationController);
    rotationAnimation = Tween<double>(begin: 180.0, end: 0.0).animate(
        CurvedAnimation(parent: animationController, curve: Curves.easeOut));
    super.initState();
    animationController.addListener(() {
      setState(() {});
    });
  }

  @override
  Widget build(BuildContext context) {
    Size size = MediaQuery.of(context).size;
    return Scaffold(
      appBar: AppBar(
        title: const Text('Test page'),
      ),
      body: ListView.separated(
        padding: const EdgeInsets.all(8),
        itemCount: 50,
        itemBuilder: (BuildContext context, int index) {
          return Container(
            height: 50,
            color: Colors.blue,
            child: Center(child: Text('Entry ${index}')),
          );
        },
        separatorBuilder: (BuildContext context, int index) => const Divider(),
      ),
      floatingActionButton: Stack(
        children: <Widget>[
          Positioned(
              right: 30,
              bottom: 30,
              child: Stack(
                alignment: Alignment.bottomRight,
                children: <Widget>[
                  IgnorePointer(
                    child: Container(
                      color: Colors.white.withOpacity(
                          0.0), // comment or change to transparent color
                      height: 150.0,
                      width: 150.0,
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(270),
                        degOneTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(
                          getRadiansFromDegree(rotationAnimation.value))
                        ..scale(degOneTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.red,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.add,
                          color: Colors.white,
                        ),
                        onClick: () {
                          print('First Button');
                        },
                      ),
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(240),
                        degTwoTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(
                          getRadiansFromDegree(rotationAnimation.value))
                        ..scale(degTwoTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.black54,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.shop_two,
                          color: Colors.white,
                        ),
                        onClick: () {
                          print('Second button');
                        },
                      ),
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(210),
                        degThreeTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(
                          getRadiansFromDegree(rotationAnimation.value))
                        ..scale(degThreeTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.black54,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.equalizer,
                          color: Colors.white,
                        ),
                        onClick: () {
                          print('Third Button');
                        },
                      ),
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(180),
                        degFourTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(
                          getRadiansFromDegree(rotationAnimation.value))
                        ..scale(degFourTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.black54,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.settings,
                          color: Colors.white,
                        ),
                        onClick: () {
                          print('Fourth Button');
                        },
                      ),
                    ),
                  ),
                  Transform(
                    transform: Matrix4.rotationZ(
                        getRadiansFromDegree(rotationAnimation.value)),
                    alignment: Alignment.center,
                    child: CircularButton(
                      color: Colors.red,
                      width: 60,
                      height: 60,
                      icon: Icon(
                        Icons.menu,
                        color: Colors.white,
                      ),
                      onClick: () {
                        if (animationController.isCompleted) {
                          animationController.reverse();
                        } else {
                          animationController.forward();
                        }
                      },
                    ),
                  )
                ],
              ))
        ],
      ),
    );
  }
}

class CircularButton extends StatelessWidget {
  final double width;
  final double height;
  final Color color;
  final Icon icon;
  final Function onClick;

  CircularButton(
      {this.color, this.width, this.height, this.icon, this.onClick});

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(color: color, shape: BoxShape.circle),
      width: width,
      height: height,
      child: IconButton(icon: icon, enableFeedback: true, onPressed: onClick),
    );
  }
}

Answer 3

内容不可见，因为您正在为自定义 FAB 使用脚手架

import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/painting.dart';
//import 'constants.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Mandaboo',
      theme: ThemeData(

      ),
      home: MyHomePage(
      ),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(child: Text('hi i\'m content'),),
        floatingActionButton: CustomFAB(),
    );
  }
}


class CustomFAB extends StatefulWidget {
  @override
  _CustomFABState createState() => _CustomFABState();
}

class _CustomFABState extends State<CustomFAB> with SingleTickerProviderStateMixin {

  AnimationController animationController;
  Animation degOneTranslationAnimation,degTwoTranslationAnimation,degThreeTranslationAnimation, degFourTranslationAnimation;
  Animation rotationAnimation;


  double getRadiansFromDegree(double degree) {
    double unitRadian = 57.295779513;
    return degree / unitRadian;
  }

  @override
  void initState() {
    animationController = AnimationController(vsync: this,duration: Duration(milliseconds: 250));
    degOneTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 1.2), weight: 75.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 1.2,end: 1.0), weight: 25.0),
    ]).animate(animationController);
    degTwoTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 1.4), weight: 55.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 1.4,end: 1.0), weight: 45.0),
    ]).animate(animationController);
    degThreeTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 1.75), weight: 35.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 1.75,end: 1.0), weight: 65.0),
    ]).animate(animationController);
    degFourTranslationAnimation = TweenSequence([
      TweenSequenceItem<double>(tween: Tween<double >(begin: 0.0,end: 2.10), weight: 15.0),
      TweenSequenceItem<double>(tween: Tween<double>(begin: 2.10,end: 1.0), weight: 85.0),
    ]).animate(animationController);
    rotationAnimation = Tween<double>(begin: 180.0,end: 0.0).animate(CurvedAnimation(parent: animationController
        , curve: Curves.easeOut));
    super.initState();
    animationController.addListener((){
      setState(() {

      });
    });
  }


  @override
  Widget build(BuildContext context) {
    Size size = MediaQuery.of(context).size;
    return Container(
      width: size.width,
      height: size.height,
      child: Stack(
        children: <Widget>[
          Positioned(
              right: 30,
              bottom: 30,
              child: Stack(
                alignment: Alignment.bottomRight,
                children: <Widget>[
                  IgnorePointer(
                    child: Container(
                      color: Colors.white.withOpacity(0.0), // comment or change to transparent color
                      height: 150.0,
                      width: 150.0,
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(270),degOneTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degOneTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.red,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.add,
                          color: Colors.white,
                        ),
                        onClick: (){
                          print('First Button');
                        },
                      ),
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(240),degTwoTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degTwoTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.black54,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.shop_two,
                          color: Colors.white,
                        ),
                        onClick: (){
                          print('Second button');
                        },
                      ),
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(210),degThreeTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degThreeTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.black54,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.equalizer,
                          color: Colors.white,
                        ),
                        onClick: (){
                          print('Third Button');
                        },
                      ),
                    ),
                  ),
                  Transform.translate(
                    offset: Offset.fromDirection(getRadiansFromDegree(180),degFourTranslationAnimation.value * 100),
                    child: Transform(
                      transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value))..scale(degFourTranslationAnimation.value),
                      alignment: Alignment.center,
                      child: CircularButton(
                        color: Colors.black54,
                        width: 40,
                        height: 40,
                        icon: Icon(
                          Icons.settings,
                          color: Colors.white,
                        ),
                        onClick: (){
                          print('Fourth Button');
                        },
                      ),
                    ),
                  ),
                  Transform(
                    transform: Matrix4.rotationZ(getRadiansFromDegree(rotationAnimation.value)),
                    alignment: Alignment.center,
                    child: CircularButton(
                      color: Colors.red,
                      width: 60,
                      height: 60,
                      icon: Icon(
                        Icons.menu,
                        color: Colors.white,
                      ),
                      onClick: (){
                        if (animationController.isCompleted) {
                          animationController.reverse();
                        } else {
                          animationController.forward();
                        }
                      },
                    ),
                  )

                ],
              ))
        ],
      ),
    );
  }
}


class CircularButton extends StatelessWidget {

  final double width;
  final double height;
  final Color color;
  final Icon icon;
  final Function onClick;

  CircularButton({this.color, this.width, this.height, this.icon, this.onClick});


  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(color: color,shape: BoxShape.circle),
      width: width,
      height: height,
      child: IconButton(icon: icon,enableFeedback: true, onPressed: onClick),
    );
  }
}

I/where 如何将自定义动画浮动操作按钮置于主要 page/content 之上？扑

How do I/where do I put a custom Animated Floating Action Button to be on top of the main page/content? flutter

flutter

button

action

floating