如何在flutter中从画廊上传视频

dependencies:
  image_picker: ^0.8.4+4
  video_player: ^2.2.5

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

class VideoUploader extends StatefulWidget {
  @override
  _VideoUploaderState createState() => _VideoUploaderState();
}

class _VideoUploaderState extends State<VideoUploader> {
  VideoPlayerController? _controller;
  bool _isVideoSelected = false;

  Future<void> _pickVideo() async {
    final pickedFile = await ImagePicker().getVideo(source: ImageSource.gallery);
    if (pickedFile != null) {
      _controller = VideoPlayerController.file(File(pickedFile.path));
      await _controller!.initialize();
      setState(() {
        _isVideoSelected = true;
      });
    }
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Video Uploader'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            if (_isVideoSelected)
              AspectRatio(
                aspectRatio: _controller!.value.aspectRatio,
                child: VideoPlayer(_controller!),
              ),
            ElevatedButton(
              onPressed: _pickVideo,
              child: Text('选择视频'),
            ),
          ],
        ),
      ),
    );
  }
}

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Video Uploader',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: VideoUploader(),
    );
  }
}