netcore 上传文件到阿里云OSS问题

AliYunOSSHelper类：

namespace VOL.WebApi
{public class AliYunOSSHelper: IScopedDependency{private ILogger _logger;/// <summary>/// 阿里云帮助类/// </summary>/// <param name="logger"></param>/// <param name="configHelper"></param>public AliYunOSSHelper(ILogger<AliYunOSSHelper> logger){_logger = logger;}public AliYunOSSHelper(){}/// <summary>/// 阿里云上传底层方法，文件为IFormFile/// </summary>/// <param name="shop_code"></param>/// <param name="files"></param>/// <returns></returns>public async Task<List<string>> AliYunUpLoad(List<IFormFile> files/*, string name*/){List<string> ossfilesNameList = new List<string>();try{//阿里云oss相关参数,请自行补齐  oss-cn-shenzhen-internal.aliyuncs.com  aapi.oss-cn-shenzhen-internal.aliyuncs.com  //账户1//var endpoint = "https://oss-cn-beijing.aliyuncs.com";//var accessKeyId = "*";//var accessKeySecret = "*";//var bucket = "aapi";//var imageUrl = "https://*.oss-cn-beijing.aliyuncs.com";//账户2var endpoint = "http://oss-cn-beijing.aliyuncs.com";var accessKeyId = "*";var accessKeySecret = "*";var bucket = "cdn*";var imageUrl = "http://cdn*.oss-cn-beijing.aliyuncs.com";var write_client = new OssClient(endpoint, accessKeyId, accessKeySecret);var read_client = new OssClient(endpoint, accessKeyId, accessKeySecret);for (int i = 0; i < files.Count; i++){var file = files[i];var fname = DateTime.Now.ToString("yyyyMMddHHmmssffffff") + i + Path.GetExtension(file.FileName);using (var stream = file.OpenReadStream()){write_client.PutObject(bucket, fname, stream);}DateTime expiration = DateTime.Now.AddYears(20);var url = read_client.GeneratePresignedUri(bucket, fname, expiration);string urlstring = imageUrl + url.AbsolutePath;ossfilesNameList.Add(urlstring);}}catch (Exception ex){_logger.LogError(ex, "阿里云图片上传失败,ex=" + ex.Message);throw;}return ossfilesNameList;}}
}

启动项目注入：

services.AddScoped<AliYunOSSHelper>();

接口：

AliyunController

sing Aliyun.OSS;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using VOL.Core.Controllers.Basic;
using VOL.Service.IServices;
using VOL.Service.Services;namespace VOL.WebApi.Controllers
{[ApiController][Route("[controller]")]public class AliyunController : ControllerBase{public AliyunController(){ }private readonly AliYunOSSHelper _oSSHelper=new AliYunOSSHelper();/ <summary>/ 构造函数/ </summary>/ <param name="projectAppService"></param>//public AliyunStsController(AliYunOSSHelper oSSHelper)//{//    _oSSHelper = oSSHelper;//}/// <summary>/// 通用的图片上传,支持多图片上传 /// </summary>/// <param name="files"></param>/// <returns></returns>[HttpPost, Route("UploadPic"), AllowAnonymous][DisableRequestSizeLimit]public async Task<ActionResult> UploadPic(List<IFormFile> files){//15Mvar maxRequestLength = 1024 * 1024 * 15;List<string> filesName = new List<string>();if (files.Count == 0)    return Content("NoFile"+files.Count+ filesName, "text/html");else{for (var i = 0; i < files.Count; i++){var file = files[i];if (null == file || file.Length <= 0)return Content("格式不正确！", "text/html");if (file.Length > maxRequestLength){return Content("文件大小超出限制！", "text/html");}var fname = DateTime.Now.ToString("yyyyMMddHHmmssffffff") + i + Path.GetExtension(file.FileName);// if (!FileExtensionFun.CheckImageFileType(fname))//{//    return Content("上传的图片格式不正确", "text/html");//}}filesName = await _oSSHelper.AliYunUpLoad(files);}return Content(string.Join(",", filesName), "text/html");}} 
}

上传报错：