6-14-1 加入底部彈框選擇拍照或相簿

import 'package:flutter/material.dart';
import 'dart:io';
import 'package:image_picker/image_picker.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: '拍照',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: PhotoPage(title: '拍照App'),
    );
  }
}

class PhotoPage extends StatefulWidget {
  PhotoPage({Key key, this.title}) : super(key: key);

  final String title;

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

class _PhotoPageState extends State<PhotoPage> {
  File _image;
  final picker = ImagePicker();

  Future getImage(bool isTakePhoto) async {
    //去除底部彈框
    Navigator.pop(context);
    final pickedFile = await picker.getImage(source: isTakePhoto?ImageSource.camera:ImageSource.gallery);

    setState(() {
      if (pickedFile != null) {
        _image = File(pickedFile.path);
      } else {
        print('No image selected.');
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              '相片列表',
              style: Theme.of(context).textTheme.headline4,
            ),
            _image == null
                ? Text('No image selected.')
                : Image.file(_image),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _pickImage,
        tooltip: '選擇圖片',
        child: Icon(Icons.add_a_photo),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }

  void _pickImage() {
    //底部彈框
    showModalBottomSheet(context: context, builder: (context)=>Container(
      height: 140.0,
      child: Column(
        children: [
          _item('相機拍照', true),
          _item('從相簿選擇', false)
        ],
      ),
    ));
  }

  _item(String title, bool isTakePhoto) {
    return GestureDetector(
      child: ListTile(
        leading: Icon(isTakePhoto?Icons.camera_alt:Icons.photo_album),
        title:Text(title),
        onTap: ()=>getImage(isTakePhoto),
      ),
    );
  }
}