小部件中的颤动相机预览，而不是全屏

Question

有什么方法可以创建一个 Flutter 小部件，该小部件将是一个绝对位置（在 CSS 中），该小部件内的哪个将是相机预览？

我已经创建了小部件，当我访问页面时，我可以在屏幕的右下角看到它，但是当我从 Flutter 添加 CameraPreview 插件时，它会使其全屏显示。

我需要的是在我创建的页面/屏幕的右下角小部件上进行应用程序预览的选项。

Square 小部件，是我只想显示相机的地方。

import 'package:flutter/material.dart';

[![class CameraAppTest extends StatelessWidget {
  static const routeName = '/videoRecordScreen';
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('test'),
      ),
      body: Container(
        // width: 200,
        alignment: Alignment.center,
        // margin: EdgeInsets.all(24),
        // padding: EdgeInsets.all(24),
        decoration: BoxDecoration(),
        // decoration: ,
        child: Container(child: Demo()),
      ),
    );
  }
}

class Square extends StatelessWidget {
  final color;
  final size;

  Square({this.color, this.size});
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Icon(Icons.add),
    );
  }
}

class Demo extends StatelessWidget {
  build(context) {
    return Container(
      margin: EdgeInsets.only(bottom: 20, right: 20),
      height: MediaQuery.of(context).size.height,
      width: MediaQuery.of(context).size.width,
      child: Stack(
        children: \[
          Align(
            alignment: Alignment.bottomRight,
            child: ClipRRect(
              borderRadius: BorderRadius.all(Radius.circular(20)),
              child: Container(
                width: 200,
                height: 200,
                decoration: BoxDecoration(
                  border: Border.all(width: 10, color: Colors.black),
                ),
                // margin: EdgeInsets.only(bottom: 30),
                child: Square(),
              ),
            ),
          ),
          // Square(),
        \],
      ),
    );
  }
}][1]][1]

请检查下面的图片，了解我想在右下角放置相机小部件的位置。谢谢你，米洛。

Answer 1

您可以在下面复制粘贴运行完整代码
您可以初始化相机并更新Square到以下
代码片段

import 'package:camera/camera.dart';
...
class _SquareState extends State<Square> {
  CameraController controller;

  @override
  void initState() {
    super.initState();
    controller = CameraController(cameras[0], ResolutionPreset.medium);
    controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    });
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (!controller.value.isInitialized) {
      return Container();
    }
    return AspectRatio(
        aspectRatio: controller.value.aspectRatio,
        child: CameraPreview(controller));
  }
}

工作演示

完整代码

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

List<CameraDescription> cameras;

class CameraAppTest extends StatelessWidget {
  static const routeName = '/videoRecordScreen';
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('test'),
      ),
      body: Container(
        // width: 200,
        alignment: Alignment.center,
        // margin: EdgeInsets.all(24),
        // padding: EdgeInsets.all(24),
        decoration: BoxDecoration(),
        // decoration: ,
        child: Container(child: Demo()),
      ),
    );
  }
}

class Square extends StatefulWidget {
  final color;
  final size;

  Square({this.color, this.size});

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

class _SquareState extends State<Square> {
  CameraController controller;

  @override
  void initState() {
    super.initState();
    controller = CameraController(cameras[0], ResolutionPreset.medium);
    controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    });
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (!controller.value.isInitialized) {
      return Container();
    }
    return AspectRatio(
        aspectRatio: controller.value.aspectRatio,
        child: CameraPreview(controller));
  }
}

class Demo extends StatelessWidget {
  build(context) {
    return Container(
      margin: EdgeInsets.only(bottom: 20, right: 20),
      height: MediaQuery.of(context).size.height,
      width: MediaQuery.of(context).size.width,
      child: Stack(
        children: [
          Align(
            alignment: Alignment.bottomRight,
            child: ClipRRect(
              borderRadius: BorderRadius.all(Radius.circular(20)),
              child: Container(
                width: 200,
                height: 200,
                decoration: BoxDecoration(
                  border: Border.all(width: 10, color: Colors.black),
                ),
                // margin: EdgeInsets.only(bottom: 30),
                child: Square(),
              ),
            ),
          ),
          // Square(),
        ],
      ),
    );
  }
}

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  cameras = await availableCameras();
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: CameraAppTest(),
    );
  }
}

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

  final String title;

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

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

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}