[移动开发]flutter 下载文件到应用内

path_provider: ^1.6.14
dio: ^3.0.10

path_provider getTemporaryDirectory 获取应用内临时地址
dio.download 下载网络地址url上的文件

 final Directory appDirectory = await getTemporaryDirectory();
 String savePath = appDirectory.path + '/file.bin';

 Dio dio = new Dio();
 dio.options.connectTimeout = 10000; //设置连接超时时间
 dio.options.receiveTimeout = 10000;  //设置数据接收超时时间
 Response response;
 
 try {
   response = await dio.download(url, savePath);
   if (response.statusCode == 200) { //下载文件成功
     final file = File(savePath);
     Uint8List content = await file.readAsBytes();
     print('length ${content.length}');
   } 
   else {
     throw Exception('接口出错');
   }
 } catch (e) {
   throw Exception('下载文件失败');
 }
}