将大文件pdf，xlsx存储到indexedDB中并从那里下载

Question

我试图将文件保存到索引数据库中，并在系统脱机后从索引数据库下载该文件。面临两个问题。

1. 下载后我推送到db的文件无法打开文件。
2. 当大文件之类的东西超过150 MB时，其面包屑会在JSON.stringify（）中产生错误

将我的代码放在下面。请帮我拼命完成这个任务。是否有任何其他任何更好的方法做错了，甚至任何导致它正确的线索都将是有益的

    downloadfile() {
                var self = this;
                var getComment = 'http://localhost/PWAS/CommentService/api/Products/GetbookFor?format=xlsx';
                this.httpservice.get(getComment).then(function (response) {
                    self.saveData(response.data, "sampleFile.xlsx");
                });
            }

saveData = (function () {
            var a = document.createElement("a");
            document.body.appendChild(a);
            // a.style = "display: none";
            return function (data, fileName) {
                var json = JSON.stringify(data),
                    blob = new Blob([json], { type: "octet/stream" }),
                    url = window.URL.createObjectURL(blob);
                a.href = url;
                a.download = fileName;
                a.click();
                window.URL.revokeObjectURL(url);
            };
        }());

在线时正在获取文件并放入索引数据库。我正在使用http拦截器

 'response': function (response) {
            if (response.config.method == 'GET' && isAUserDataCall(response.config.url)) {
                if (navigator.onLine) {
                    if (isdocumentDownload(response.config.url)) {
                        var data = { value: JSON.stringify(response) };
                        var key = response.config.url;
                        update('OfflineDB', 'UserData', data, key);
                    }
                    else {
                        var data = { value: JSON.stringify(response.data) };
                        var key = response.config.url;
                        update('OfflineDB', 'UserData', data, key);
                    }
                }
            }
            return response;
        },

function update(dbName, storeName, data, key,isdirectData) {
    var openRequest = openDB(dbName, storeName);
    openRequest.onsuccess = function (e) {
        console.log("Success!");
        db = e.target.result;
        updateUserDataResponse(storeName, data, key,isdirectData);
    }
    openRequest.onerror = function (e) {
        console.log("Error");
        console.dir(e);
    }
}


function updateUserDataResponse(storeName, data, key, isdirectData) {
    selectfromDBbyKey(storeName, key).then(function (response) {
        var transaction = db.transaction([storeName], "readwrite");
        var store = transaction.objectStore(storeName);
        if (isdirectData)
            var request = store.put(data, key);
        else
            var request = store.put(data.value, key);
        request.onerror = function () {
            console.log("Error");
        }
        request.onsuccess = function () {
            console.log("Yolo! Did it");
        }
    });
}

我的服务是下载

[HttpGet]
        public HttpResponseMessage GetbookFor(string format)
        {
            HttpResponseMessage result = null;
            var localFilePath = HttpContext.Current.Server.MapPath("~/App_Data/Comments.pdf");

            if (!File.Exists(localFilePath))
            {
                result = Request.CreateResponse(HttpStatusCode.Gone);
            }
            else
            {
                // Serve the file to the client
                result = Request.CreateResponse(HttpStatusCode.OK);
                result.Content = new StreamContent(new FileStream(localFilePath, FileMode.Open, FileAccess.Read));
                result.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
                result.Content.Headers.ContentDisposition.FileName = "Comments.pdf";
            }

            return result;
        }

 public class eBookResult : IHttpActionResult
    {

        string PdfFileName;
        HttpRequestMessage httpRequestMessage;
        HttpResponseMessage httpResponseMessage;
        public eBookResult(MemoryStream data, HttpRequestMessage request, string filename)
        {
            httpRequestMessage = request;
            PdfFileName = filename;
        }

        Task<HttpResponseMessage> IHttpActionResult.ExecuteAsync(CancellationToken cancellationToken)
        {
            MemoryStream bookStuff = new MemoryStream();
            httpResponseMessage = httpRequestMessage.CreateResponse(HttpStatusCode.OK);
            httpResponseMessage.Content = new StreamContent(bookStuff);
            //httpResponseMessage.Content = new ByteArrayContent(bookStuff.ToArray());  
            httpResponseMessage.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
            httpResponseMessage.Content.Headers.ContentDisposition.FileName = PdfFileName;
            httpResponseMessage.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");

          //  Thread.Sleep(200000);

            return System.Threading.Tasks.Task.FromResult(httpResponseMessage);
        }
    }