使用Flutter的image_picker插件实现设备的相册的访问和拍照

import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
 
void main() => runApp(MyApp());
 
class MyApp extends StatelessWidget {
  // 此处省略其他代码...
 
  Future<void> _pickImage(ImageSource source) async {
    // 这里使用了`ImagePicker`插件来选择图片
    final ImagePicker _picker = ImagePicker();
    final XFile? image = await _picker.pickImage(source: source);
 
    if (image != null) {
      setState(() {
        _imageFile = File(image.path); // 更新_imageFile状态
      });
    }
  }
 
  // 此处省略其他代码...
}
 
class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}
 
class _MyAppState extends State<MyApp> {
  File? _imageFile;
 
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      // 此处省略其他代码...
      floatingActionButton: Column(
        crossAxisEnd: CrossAxisAlignment.end,
        mainAxisEnd: MainAxisAlignment.end,
        children: <Widget>[
          FloatingActionButton(
            onPressed: () => _pickImage(ImageSource.gallery),
            tooltip: 'Pick Image from Gallery',
            child: Icon(Icons.photo_library),
          ),
          SizedBox(height: 8.0), // 添加间隔
          FloatingActionButton(
            onPressed: () => _pickImage(ImageSource.camera),
            tooltip: 'Take a Photo',
            child: Icon(Icons.camera_alt),
          ),
        ],
      ),
    );
  }
 
  // 此处省略_pickImage函数的实现...
}

这个代码实例展示了如何在Flutter应用中使用image_picker插件来实现从相册中选择图片和拍照的功能。在_MyAppState类中，我们定义了一个_pickImage方法来处理图片的选择，并在构建方法中创建了两个浮动按钮来分别调用选择相册和拍照的功能。这个例子简洁明了，并且注重于展示核心的图片选择逻辑。