net core 图片上传

前端代码：

  <div class="ext_tempfileupload" data-fileupload-for="Img">
                    <span class="btn btn-success">
                        <span class="glyphicon glyphicon-plus "></span>
                        <span>上传</span>
                    </span>
                </div>

   $.fn.extend({
            nyUpload: function (options) {
                var $this = $(this);
                let $fileUploadInfoSpan = $("<span></span>");
                let $file = $("<input type='file' style='display:none;'/>")
                    .on("change", function () {
                        var formFile = new FormData();
                        for (var i = 0; i < $(this)[0].files.length; i++) {
                            formFile.append($(this)[0].files[i].name, $(this)[0].files[i]);
                        }
                        if (!formFile) {
                            return;
                        }

                        $fileUploadInfoSpan.text("(准备上传)");
                         var url ="@Url.Action(nameof(NY.CCP.StatelliteWebApp.Controllers.Webs.InfoController.AjaxMultiFileUploadAsync))";
                        $.ajax({
                            url: url,
                            data: formFile ,
                            type: "POST",
                            processData: false,   // jQuery不要去处理发送的数据
                            contentType: false,   // jQuery不要去设置Content-Type请求头
                            success: function (data) {
                                $fileUploadInfoSpan.text("(上传成功)");
                                var dastr = eval(data);
                                var json = eval(dastr.filePathArray);

                                var htmlImg = "";
                                for (var i = 0; i < json.length; i++) {
                                    htmlImg += "<div class="col-4"> <div class="card "> <img class="card-img - top img - thumbnail" src="" + json[i].filePath+"" alt="Card image cap"></div></div>";
                                }

                                $("#fileImgs").append(htmlImg);
                            },
                            error: function(){
                                $fileUploadInfoSpan.text("(获取上传信息失败)");
                                options.error && options.error("获取上传信息失败");
                            }
                        });
                    });

                if (options.accept) {
                    $file.attr("accept", options.accept);
                }
                if (options.multiple) {
                    $file.attr("multiple", options.multiple);
                }

                $this.append($fileUploadInfoSpan).after($file).on("click", function () { $file[0].click(); });
            }
        });

        $(function () {
            //
            $(".ext_tempfileupload").each(function (index,item) {
                let $this = $(item);
                //关联的图片input
                let $fileIdInput = $("#" + $this.data("forinput-fileid"));
                let $fileUrlInput = $("#" + $this.data("forinput-fileurl"));
                let $fileImg = $("#" + $this.data("forimg"));

                $this.nyUpload({
                    accept: $this.data("accept"),
                    multiple: $this.data("multiple"),
                    error: function (msg) { },
                    success: function (data) {
                        if ($fileIdInput) {
                            $fileIdInput.val(data.fileId);
                        }
                        if ($fileUrlInput) {
                            $fileUrlInput.val(data.location);
                        }
                        if ($fileImg) {
                            $fileImg.show().attr("src", data.location);
                        }
                    }
                });
            });


        });

 后台代码：

  private static IHostingEnvironment _hostingEnvironment;

        /// <summary>
        /// 对文件上传响应模型
        /// </summary>
        class UploadFileRequest
        {
            /// <summary>
            /// 文件名称
            /// </summary>
            public string FileName { get; set; }

            /// <summary>
            /// 文件路径
            /// </summary>
            public string FilePath { get; set; }
        }

        public InfoController(IHostingEnvironment hostingEnvironment)
        {
            _hostingEnvironment = hostingEnvironment;
        }

/// <summary>
        ///  多图片上传
        /// </summary>
        /// <param name="formCollection">表单集合值</param>
        /// <returns>服务器存储的文件信息</returns>
        public async Task<JsonResult> AjaxMultiFileUploadAsync(IFormCollection formCollection)
        {
            var currentDate = DateTime.Now;
            var webRootPath = _hostingEnvironment.WebRootPath;//>>>相当于HttpContext.Current.Server.MapPath("") 

            var uploadFileRequestList = new List<UploadFileRequest>();
            var pathList = new List<string>();
            var srcPathList = new List<string>();

            try
            {
                //FormCollection转化为FormFileCollection
                var files = (FormFileCollection)formCollection.Files;

                if (files.Any())
                {
                    foreach (var file in files)
                    {
                        var uploadFileRequest = new UploadFileRequest();

                        var filePath = $"/UploadFile/{currentDate:yyyyMMdd}/";

                        //创建每日存储文件夹
                        if (!Directory.Exists(webRootPath + filePath))
                        {
                            Directory.CreateDirectory(webRootPath + filePath);
                        }

                        //文件后缀
                        var fileExtension = Path.GetExtension(file.FileName);//获取文件格式，拓展名

                        //判断文件大小
                        var fileSize = file.Length;

                        if (fileSize > 1024 * 1024 * 10) //10M TODO:(1mb=1024X1024b)
                        {
                            continue;
                        }

                        //保存的文件名称(以名称和保存时间命名)
                        var saveName = file.FileName.Substring(0, file.FileName.LastIndexOf('.')) + "_" + currentDate.ToString("HHmmss") + fileExtension;

                        //文件保存
                        using (var fs = System.IO.File.Create(webRootPath + filePath + saveName))
                        {
                            file.CopyTo(fs);
                            fs.Flush();
                        }

                        //完整的文件路径
                        var completeFilePath = Path.Combine(filePath, saveName);

                        uploadFileRequestList.Add(new UploadFileRequest()
                        {
                            FileName = saveName,
                            FilePath = completeFilePath
                        });
                        pathList.Add(Utils.CloudFilePathUtils.GetTempImgFilePath(saveName));
                        srcPathList.Add(webRootPath + filePath + saveName);
                    }
                }
                else
                {
                    return new JsonResult(new { isSuccess = false, resultMsg = "上传失败，未检测上传的文件信息~" });
                }
            }
            catch (Exception ex)
            {
                return new JsonResult(new { isSuccess = false, resultMsg = "文件保存失败，异常信息为：" + ex.Message });
            }

            if (uploadFileRequestList.Any())
            {

//CosSDK.TransferBatchUploadObjects(pathList, srcPathList);
//foreach (var item in pathList)
//{
// uploadFileRequestList.Add(new UploadFileRequest()
// {
// FileName = item,
// FilePath = CosSDK.GetObjectUrlWithAuthorization(item, QCloudSDK.Models.Cos.ProtocolType.Https, QCloudSDK.Models.Cos.LineType.Cdn, null)
// });
//}

            }



            return new JsonResult(new { isSuccess = true, returnMsg = "上传成功", filePathArray = uploadFileRequestList });
        }
            else
            {
                return new JsonResult(new { isSuccess = false, resultMsg = "网络打瞌睡了，文件保存失败" });
            }
        }