【Flutter】抽象类的运用（abstract与implements的实践）

使用场景：功能支持两种接口模式，使用抽象类分别实现接口
1、定义抽象类及统一接口

abstract class UploadStrategy {/// 抽象上传方法/// [file]：待上传文件/// [onSendProgress]：进度回调（已上传字节数，总字节数）Future<String> upload({required File file,Function(int, int)? onSendProgress});
}

2、通过创建策略工厂类（根据类型获取上传实例）

class UploadStrategyFactory {static UploadStrategy getStrategy(UploadApiType type) {switch (type) {case UploadApiType.aLiYun:return AliYunUploader();case UploadApiType.sam:return SamUploader();}}
}

3、通过implements分别实现自定义上传接口

/// 阿里云OSS上传实现
class AliYunUploader implements UploadStrategy {@overrideFuture<String> upload({required File file,Function(int, int)? onSendProgress}) async {// 复用原阿里云上传逻辑return await AliyunOss.upload(file: file,onSendProgress: onSendProgress,);}
}//上传实现
class SamUploader implements UploadStrategy {@overrideFuture<String> upload({required File file,Function(int, int)? onSendProgress}) async {return await FileUploadService().uploadCommon(file);}
}

4、使用示例：

 final uploader = UploadStrategyFactory.getStrategy(uploadType);try {final urls = await Future.wait(files.map((file) => uploader.upload(file: file,onSendProgress: onSendProgress,),),);UIToast.showSuccess('上传成功');successCallback(urls);} catch (e) {UIToast.showError('上传失败: ${e.toString()}');} finally {UIToast.dismissHud();}

总结：虽然可以通过参数方式实现不同类型接口的功能，但通过抽象类可以减少逻辑，并更加简便的使用上传方法，后期若有增加类型，也更容易维护。