flutter开发实战-dio文件下载实现
在开发中,需要下载文件,这里使用的是dio
dio 是一个强大的 Dart HTTP 请求库,支持全局配置、Restful API、FormData、拦截器、 请求取消、Cookie 管理、文件上传/下载、超时以及自定义适配器等。
一、引入dio
在工程中pubspec.yaml引入dio
dio: ^5.1.1dio_cookie_manager: ^3.0.0
二、代码实现
我们对dio进行封装
// 定义枚举,请求方法枚举
enum HttpApiMethod {GET,POST,DELETE,PUT,
}// 网络请求的成功与失败
// 上传
typedef OnUploaded = void Function(Map<String, dynamic> result);
// 下载进度
typedef OnDownloadProgress = void Function(int count, int total);
// 下载成功
typedef OnDownloaded = void Function();
// 请求成功
typedef OnSuccess = void Function(ResponseData responseData);
// 请求失败
typedef OnFailure = void Function(ApiHttpError error);// 请求Api
class HttpApi {// 网络请求库dioDio dio = Dio(BaseOptions(// connectTimeout: 60000, // 连接服务器超时时间,单位是毫秒.// receiveTimeout: 10000, // 响应流上前后两次接受到数据的间隔,单位为毫秒, 这并不是接收数据的总时限headers: {HttpHeaders.acceptHeader: "text/plain,""text/plain,""multipart/form-data,""application/json,""text/html,""image/jpeg,""image/png,""application/octet-stream,""text/json,""text/javascript,""text/html",},));// 私有构造函数HttpApi._internal();//保存单例static HttpApi _singleton = HttpApi._internal();//工厂构造函数factory HttpApi() => _singleton;/// 配置请求头header/// /// The request Content-Type. The default value is 'application/json; charset=utf-8'.// /// If you want to encode request body with 'application/x-www-form-urlencoded',// /// you can set [Headers.formUrlEncodedContentType], and [Dio]// /// will automatically encode the request body.Future<void> configHeaders(String requestUrl, Map<String, dynamic>? params) async {dio.options.headers['Content-Type'] = Headers.jsonContentType;LoggerManager().info("requestUrl:${requestUrl} dio.options.headers:${dio.options.headers}");}get(String url, ApiServiceDomain serviceDomain,{Map<String, dynamic>? params, OnSuccess? success, OnFailure? failure}) {doRequest(url, serviceDomain, HttpApiMethod.GET,params: params, success: success, failure: failure);}post(String url, ApiServiceDomain serviceDomain,{Map<String, dynamic>? params, OnSuccess? success, OnFailure? failure}) {doRequest(url, serviceDomain, HttpApiMethod.POST,params: params, success: success, failure: failure);}// 请求服务器// params,参数// 请求成功// 请求失败Future<void> doRequest(String url, ApiServiceDomain serviceDomain, HttpApiMethod method,{Map<String, dynamic>? params,OnSuccess? success,OnFailure? failure}) async {String requestUrl = getRequestUrl(url, serviceDomain);try {/// 可以添加headerawait configHeaders(requestUrl, params);Response? response;switch (method) {case HttpApiMethod.GET:{// get请求if (params != null && params.isNotEmpty) {response = await dio.get(requestUrl,queryParameters: params,options: Options(contentType: Headers.jsonContentType));LoggerManager().debug("await dio.get response:$response,params:$params");} else {response = await dio.get(requestUrl,options: Options(contentType: Headers.jsonContentType));}break;}case HttpApiMethod.POST:{// post请求String? contentType = Headers.formUrlEncodedContentType;if (params != null && params.isNotEmpty) {response = await dio.post(requestUrl,data: params, options: Options(contentType: contentType));LoggerManager().debug("await dio.post response:$response,params:$params");} else {response = await dio.post(requestUrl,options: Options(contentType: contentType));}break;}// case HttpApiMethod.PUT: {// break;// }// case HttpApiMethod.DELETE: {// break;// }default:}LoggerManager().debug('doRequest: $response, params:$params');if (response != null) {Map<String, dynamic> result = json.decode(response.toString());assert(() {// assert只会在debug模式下执行,release模式下不会执行// 打印信息LoggerManager().debug('''api: $requestUrl\nresult: $result''');return true;}());ResponseData responseData = ResponseData.fromJson(result);if (responseData.status == 0) {if (success != null) {//返回请求数据success(responseData);}} else {//返回失败信息ApiHttpError apiHttpError = getErrorRequestResponseData(responseData);LoggerManager().debug("apiHttpError:${apiHttpError.toString()}");LoggerManager().error('''api: $requestUrl\nresult: $result''');if (failure != null) {failure(apiHttpError);}}} else {// 没有获得response,failureApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "请求失败!");LoggerManager().debug("apiHttpError:${apiHttpError.toString()}");if (failure != null) {failure(apiHttpError);}}} on DioError catch (e, s) {// catch到异常,failure// The request was made and the server responded with a status code// that falls out of the range of 2xx and is also not 304.LoggerManager().error("doRequest api: $requestUrl, dioError:${e.message}, s:$s");ApiHttpError apiHttpError = getRequestFailure(e.response, e.type);LoggerManager().debug("apiHttpError:${apiHttpError.toString()}");if (failure != null) {failure(apiHttpError);}} catch (e) {// 可以捕获任意异常ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "${e.toString()}");if (failure != null) {failure(apiHttpError);}}}// 上传文件(图片)doUploadFile(String url, UploadFileInfo fileInfo,{Map<String, dynamic>? params,OnUploaded? uploaded,OnFailure? failure}) async {try {String timeStamp = DateTime.now().millisecondsSinceEpoch.toString();Map<String, dynamic> fromParams = Map();if (params != null && params.isNotEmpty) {fromParams.addAll(params);}fromParams["file"] = await MultipartFile.fromFile(fileInfo.file.path,filename: '${fileInfo.key}-${timeStamp}.jpg');FormData formData = FormData.fromMap(fromParams);Response? response = await dio.post(url, data: formData);assert(() {// assert只会在debug模式下执行,release模式下不会执行// 打印信息LoggerManager().error('''api: $url\nresult: $response''');return true;}());if (response != null) {Map<String, dynamic> result = json.decode(response.toString());assert(() {// assert只会在debug模式下执行,release模式下不会执行// 打印信息LoggerManager().debug('''api: $url\nresult: $result''');return true;}());if (response.statusCode == 200) {if (uploaded != null) {uploaded(result);}} else {//返回失败信息LoggerManager().error('''api: $url\nresult: $result''');ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "请求失败!");if (failure != null) {failure(apiHttpError);}}} else {//返回失败信息// 没有获得response,failureApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "请求失败!");if (failure != null) {failure(apiHttpError);}}} on DioError catch (e, s) {// catch到异常,failureLoggerManager().error("doUploadFile api: $url, dioError:$e, s:$s");ApiHttpError apiHttpError = getRequestFailure(e.response, e.type);if (failure != null) {failure(apiHttpError);}} catch (e) {// 可以捕获任意异常ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "${e.toString()}");if (failure != null) {failure(apiHttpError);}}}// 下载文件void doDownload(String url, String savePath,{required CancelToken cancelToken,Map<String, dynamic>? params,dynamic? data,Options? options,OnDownloadProgress? progress,OnDownloaded? completion,OnFailure? failure}) async {try {dio.download(url,savePath,queryParameters: params,cancelToken: cancelToken,onReceiveProgress: (int count, int total) {if (total != -1) {if (!cancelToken.isCancelled) {double downloadRatio = (count / total);if (downloadRatio == 1) {if (completion != null) {completion();}} else {if (progress != null) {progress(count, total);}}}} else {ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "无法获取文件大小,下载失败!");if (failure != null) {failure(apiHttpError);}}},);} on DioError catch (e) {ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, e.toString());if (CancelToken.isCancel(e)) {apiHttpError = ApiHttpError(ApiHttpErrorType.Cancel, "下载已取消!");} else {if (e.response != null) {apiHttpError = getRequestFailure(e.response, e.type);} else {apiHttpError = ApiHttpError(ApiHttpErrorType.Default, e.message??"");}}if (failure != null) {failure(apiHttpError);}} on Exception catch (e) {// EasyLoading.showError(e.toString());ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, e.toString());if (failure != null) {failure(apiHttpError);}} catch (e) {// 可以捕获任意异常ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, "${e.toString()}");if (failure != null) {failure(apiHttpError);}}}// 根据服务器来拼接服务器具体地址String getRequestUrl(String url, ApiServiceDomain serviceDomain) {String requestUrl = url;return requestUrl;}ApiHttpError getErrorRequestResponseData(ResponseData responseData) {//返回失败信息ApiHttpError apiHttpError =ApiHttpError(ApiHttpErrorType.Default, responseData.errorMsg);if (kNeedAuthLoginErrorCode == responseData.errorCode) {apiHttpError = ApiHttpError(ApiHttpErrorType.Auth, responseData.errorMsg);}return apiHttpError;}ApiHttpError getRequestFailure(Response? response, DioErrorType dioErrorType) {LoggerManager().error("getRequestFailure: $response, dioError:$dioErrorType");ApiHttpErrorType errorType = ApiHttpErrorType.Default;String errorMessage = "请求失败!";if (response != null) {if (dioErrorType == DioErrorType.connectionTimeout) {errorType = ApiHttpErrorType.NetWork;errorMessage = "网络链接异常!";} else if (dioErrorType == DioErrorType.sendTimeout) {errorType = ApiHttpErrorType.Timeout;errorMessage = "网络链接异常!";} else if (dioErrorType == DioErrorType.receiveTimeout) {errorType = ApiHttpErrorType.Timeout;errorMessage = "网络链接异常!";} else if (dioErrorType == DioErrorType.badResponse) {// When the server response, but with a incorrect status, such as 404, 503...if (response != null) {if (response.statusCode == 401) {errorType = ApiHttpErrorType.Auth;errorMessage = "认证失败!";} else if (response.statusCode == 400) {errorType = ApiHttpErrorType.BadRequest;errorMessage = "无效请求!";} else if (response.statusCode == 404) {errorType = ApiHttpErrorType.NotFound;errorMessage = "访问的资源丢失了!";} else if (response.statusCode == 405) {// 请求的方法错误errorType = ApiHttpErrorType.BadParamHeader;errorMessage = "参数出错!";} else if (response.statusCode! >= 500) {errorType = ApiHttpErrorType.BadRequest;errorMessage = "服务器居然累倒了!";}}} else if (dioErrorType == DioErrorType.cancel) {errorType = ApiHttpErrorType.Cancel;errorMessage = "请求已经取消";}} else {errorType = ApiHttpErrorType.NetWork;errorMessage = "网络链接异常!";}ApiHttpError apiHttpError = ApiHttpError(errorType, errorMessage);return apiHttpError;}
}/// 上传的文件类
class UploadFileInfo {File file;String key;UploadFileInfo({required this.file, required this.key});
}
文件下载页面实现实例
class DownloadPage extends StatefulWidget {const DownloadPage({Key? key,this.messages,this.uniqueId,this.arguments,}) : super(key: key);final Object? arguments;final String? messages;final String? uniqueId;State<DownloadPage> createState() => _DownloadPageState();
}class _DownloadPageState extends State<DownloadPage> {String _downloadPath ='https://dl.google.com/chrome/mac/stable/GGRO/googlechrome.dmg';double _downloadRatio = 0.0;String _downloadIndicator = '0.00%';late String _destPath;late CancelToken _token;bool _downloading = false;void initState() {getTemporaryDirectory().then((tempDir) => {_destPath = tempDir.path + 'googlechrome.dmg'});super.initState();}void _downloadFile() {if (_downloading == true) {return;}_token = CancelToken();_downloading = true;HttpApi().doDownload(_downloadPath, _destPath, cancelToken: _token,progress: (int received, int total) {// 下载进度setState(() {_downloadRatio = (received / total);if (_downloadRatio == 1) {_downloading = false;}_downloadIndicator = (_downloadRatio * 100).toStringAsFixed(2) + '%';});}, completion: () {// 下载成功_downloading = false;FlutterLoadingHud.showToast(message: "\"下载完成\"");}, failure: (error) {// 下载出错_downloading = false;FlutterLoadingHud.showToast(message: error.message);});}void _cancelDownload() {if (_downloadRatio < 1.0) {_token.cancel();_downloading = false;setState(() {_downloadRatio = 0;_downloadIndicator = '0.00%';});}}void _deleteFile() {try {File downloadedFile = File(_destPath);if (downloadedFile.existsSync()) {downloadedFile.delete();} else {FlutterLoadingHud.showToast(message: "文件不存在");}} catch (e) {FlutterLoadingHud.showToast(message: "${e.toString()}");}}Widget build(BuildContext context) {return Scaffold(resizeToAvoidBottomInset: false,appBar: AppBar(leading: AppBarIconButton(icon: Icon(Icons.arrow_back_ios),onPressed: () => {NavigatorRoute.pop()},),centerTitle: true,backgroundColor: ColorUtil.hexColor(0xffffff),foregroundColor: ColorUtil.hexColor(0x777777),elevation: 0,title: Text("下载示例",textAlign: TextAlign.center,softWrap: true,style: TextStyle(fontSize: 17,color: ColorUtil.hexColor(0x333333),fontWeight: FontWeight.w600,fontStyle: FontStyle.normal,decoration: TextDecoration.none,),),shadowColor: ColorUtil.hexColor(0xffffff),toolbarHeight: 44.0,bottomOpacity: 0.0,),body: Container(color: ColorUtil.hexColor(0xf7f7f7),alignment: Alignment.center,padding: EdgeInsets.all(10),child: Column(mainAxisAlignment: MainAxisAlignment.center,children: [Row(children: [_buildDownloadButton(),TextButton(child: Text('取消'),onPressed: () {_cancelDownload();},),TextButton(child: Text('删除',style: TextStyle(color: !_downloading ? Colors.red : Colors.grey),),onPressed: (!_downloading ? _deleteFile : null),style: ButtonStyle(),),],),SizedBox(height: 25,),Row(children: [Expanded(child: LinearProgressIndicator(backgroundColor: Colors.grey[600],value: _downloadRatio,),),SizedBox(width: 5,),Text(_downloadIndicator,style: TextStyle(color: Colors.black, fontSize: 12.0),),]),],),),);}Widget _buildDownloadButton() {return ButtonWidget(onPressed: () {_downloadFile();},child: Text("下载文件",textAlign: TextAlign.center,softWrap: true,style: TextStyle(fontSize: 16,fontWeight: FontWeight.w400,fontStyle: FontStyle.normal,color: ColorUtil.hexColor(0xffffff),decoration: TextDecoration.none,),),height: 40,width: 100.0,highlightedColor: ColorUtil.hexColor(0xff462e),bgColor: ColorUtil.hexColor(0xff462e),bgHighlightedColor: ColorUtil.hexColor(0xff462e, alpha: 0.75),enabled: true,bgDisableColor: Colors.grey,borderRadius: 22.0,);}
}
三、小结
flutter开发实战-dio文件下载实现,封装dio下载功能,实现文件下载
学习记录,每天不停进步。