关键词吉他谱,嘉兴网站快速排名优化,新城免费做网站,网站建设選平台在Flutter开发中#xff0c;网络请求是必不可少的功能。为了简化代码、提高开发效率#xff0c;我们通常会封装一个网络请求工具类。本文基于Dio库#xff0c;详细介绍如何封装一个高效、灵活、易用的网络请求工具类#xff0c;支持以下功能#xff1a;
单例模式#xf…在Flutter开发中网络请求是必不可少的功能。为了简化代码、提高开发效率我们通常会封装一个网络请求工具类。本文基于Dio库详细介绍如何封装一个高效、灵活、易用的网络请求工具类支持以下功能
单例模式确保全局只有一个Dio实例避免资源浪费。动态配置支持运行时动态修改baseUrl、headers等配置。拦截器内置日志拦截器并支持添加自定义拦截器。错误处理提供详细的错误信息支持自定义错误处理逻辑。文件上传和下载封装了文件上传和下载功能。取消请求支持取消正在进行的请求。模块化设计代码结构清晰便于维护和扩展。
通过本文你将学会如何封装一个功能强大的网络请求工具类并直接应用到你的Flutter项目中。 代码实现
import package:dio/dio.dart;
import package:flutter/foundation.dart;class HttpUtil {// 单例模式static final HttpUtil _instance HttpUtil._internal();factory HttpUtil() _instance;HttpUtil._internal() {_init();}late Dio _dio;final ListInterceptor _interceptors []; // 自定义拦截器列表CancelToken _cancelToken CancelToken(); // 用于取消请求// 初始化void _init() {_dio Dio(BaseOptions(baseUrl: https://your-api-url.com, // 默认基础地址connectTimeout: const Duration(seconds: 5), // 连接超时时间receiveTimeout: const Duration(seconds: 5), // 接收数据超时时间headers: {Content-Type: application/json; charsetUTF-8,},));// 添加默认拦截器_dio.interceptors.add(InterceptorsWrapper(onRequest: (options, handler) {if (kDebugMode) {print(Request: ${options.method} ${options.path});}return handler.next(options);},onResponse: (response, handler) {if (kDebugMode) {print(Response: ${response.statusCode} ${response.data});}return handler.next(response);},onError: (DioException e, handler) {if (kDebugMode) {print(Error: ${e.message});}return handler.next(e);},));// 添加自定义拦截器for (var interceptor in _interceptors) {_dio.interceptors.add(interceptor);}}// 添加自定义拦截器void addInterceptor(Interceptor interceptor) {_interceptors.add(interceptor);_dio.interceptors.add(interceptor);}// 动态更新基础配置void updateBaseConfig({String? baseUrl,Duration? connectTimeout,Duration? receiveTimeout,MapString, dynamic? headers,}) {_dio.options.baseUrl baseUrl ?? _dio.options.baseUrl;_dio.options.connectTimeout connectTimeout ?? _dio.options.connectTimeout;_dio.options.receiveTimeout receiveTimeout ?? _dio.options.receiveTimeout;_dio.options.headers headers ?? _dio.options.headers;}// GET请求FutureResponse get(String path, {MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {return _request(path,method: GET,queryParameters: queryParameters,options: options,cancelToken: cancelToken,);}// POST请求FutureResponse post(String path, {dynamic data,MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {return _request(path,method: POST,data: data,queryParameters: queryParameters,options: options,cancelToken: cancelToken,);}// PUT请求FutureResponse put(String path, {dynamic data,MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {return _request(path,method: PUT,data: data,queryParameters: queryParameters,options: options,cancelToken: cancelToken,);}// DELETE请求FutureResponse delete(String path, {dynamic data,MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {return _request(path,method: DELETE,data: data,queryParameters: queryParameters,options: options,cancelToken: cancelToken,);}// 文件上传FutureResponse upload(String path, {required String filePath,MapString, dynamic? data,MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {final formData FormData.fromMap({...data ?? {},file: await MultipartFile.fromFile(filePath),});return _request(path,method: POST,data: formData,queryParameters: queryParameters,options: options,cancelToken: cancelToken,);}// 文件下载FutureResponse download(String urlPath,String savePath, {MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {try {final response await _dio.download(urlPath,savePath,queryParameters: queryParameters,options: options,cancelToken: cancelToken ?? _cancelToken,);return response;} on DioException catch (e) {throw _handleError(e);}}// 通用请求方法FutureResponse _request(String path, {required String method,dynamic data,MapString, dynamic? queryParameters,Options? options,CancelToken? cancelToken,}) async {try {final response await _dio.request(path,data: data,queryParameters: queryParameters,options: Options(method: method),cancelToken: cancelToken ?? _cancelToken,);return response;} on DioException catch (e) {throw _handleError(e);}}// 取消请求void cancelRequests({CancelToken? cancelToken}) {if (cancelToken null) {_cancelToken.cancel(Request cancelled);_cancelToken CancelToken(); // 重置CancelToken} else {cancelToken.cancel(Request cancelled);}}// 错误处理String _handleError(DioException e) {switch (e.type) {case DioExceptionType.connectionTimeout:return 连接超时;case DioExceptionType.sendTimeout:return 发送请求超时;case DioExceptionType.receiveTimeout:return 接收数据超时;case DioExceptionType.badResponse:return 服务器返回错误: ${e.response?.statusCode};case DioExceptionType.cancel:return 请求已取消;case DioExceptionType.unknown:return 未知错误: ${e.message};default:return 网络错误: ${e.message};}}
}使用示例
void fetchData() async {try {final response await HttpUtil().get(/api/data);print(Data: ${response.data});} catch (e) {print(Error: $e);}
}void uploadFile() async {try {final response await HttpUtil().upload(/api/upload,filePath: /path/to/file,);print(Upload Response: ${response.data});} catch (e) {print(Error: $e);}
}void cancelRequest() {HttpUtil().cancelRequests();
}总结
通过封装这样一个网络请求工具类我们可以显著提高Flutter项目的开发效率减少重复代码同时增强代码的可维护性和扩展性。希望本文对你有所帮助
