ASP.NET Core PDF Viewer
C#: how to display, save, convert, export PDF file in server side file system or database in asp.net mvc razor project

    var myIcon = new CToolbarIcon();
    myIcon.id="myIcon";
    myIcon.event = "saveOnServer()";
    myIcon.title = "Save on server";
    myIcon.reqDoc = true;


    var myGroup = new CToolbarIconGroup();
    myGroup.name="Save Server";
    myGroup.addIcon(myIcon);

    var myTab = new CToolbar();
    myTab.id = "Customizebar";
    myTab.name = "Customize";
    myTab.addIconGroup(myGroup);

    addToolbarTab(myTab);

// demo function to save the file on server
function saveOnServer() {
    // whether the file is loaded
    if (getCurrentFileId() == "")
        return;
    // get the basic save datas from API(getSaveDatas)
    var datas = getSaveDatas();
    // set the customize calling function in userCommandProcessHandler
    datas.action = "SaveFileOnServer";
    var options = {
        type: "POST",
        url: getServerHandlerUrl(),
        async: false,
        data: datas,
        success: function (result) {
            // hide the loading panel
            $("#loading").hide();
            // get the message
            var arr = eval('(' + result + ')');
            if (arr.state == "success") {
                saveFile = arr.msg;
                // open the file that store on server
                window.open(_cacheFolder + "/" + getCurrentFileId() + "/" + saveFile);
            }
            else {
                alert(arr.msg);
            }
        },
        error: function (err) {
            $("#loading").hide();
        }
    }
    // show the loading panel
    $("#loading").show();
    // send the message
    $.ajax(options);
}

public void SaveCallBack(string fid,string savepath,string responsemsg) {

        // you can process saved pdf document here, like add watermark, ...
        var documentPath = savepath;
        RasterEdge.Imaging.Basic.BaseDocument document = null;
        if (!string.IsNullOrEmpty(documentPath))
        {
            Logger.LogFile(fid, "SaveFileOnServer: output file path " + documentPath, LogType.DEBUG);

            if (documentPath.EndsWith(".pdf"))
            {
                document = new RasterEdge.XDoc.PDF.PDFDocument(documentPath);
            }

            if (document != null)
            {
                RasterEdge.XDoc.PDF.PDFDocument pdfDoc = document as RasterEdge.XDoc.PDF.PDFDocument;

                //  post-process
                String creatorName = "Hello";    //  creator name
                postSaveFileProcess(pdfDoc, creatorName);

                // get the upload information of the file
                RasterEdge.WDP.DocUploadInfo docinfo = RasterEdge.WDP.Manager.FileManager.getUploadinfoByFid(fid);

                string filename = docinfo.FileName;
                // get your file open url parameters value, if needed.
                string paraFilepathValue = docinfo.GetRequestParameters("yourtarget");

                RasterEdge.XDoc.PDF.PDFMetadata metadata = pdfDoc.GetDescription();
                metadata.Producer = "RasterEdge EdgePDF";
                pdfDoc.SetDescription(metadata);

                try
                {
                    //pdfDoc.Save(docinfo.LoadPath);
                    //pdfDoc.Save(@"C:\temp\test.pdf");
                    pdfDoc.Save(@"C:\temp\" + paraFilepathValue);
                }
                catch (Exception ex)
                {
                    // process error code, and return error information here
                    Logger.LogFile(fid, ex.Message + ". fail to save file to server.", LogType.ERROR);
                }
            }
            else
            {
                Logger.LogFile(fid, "output PDF file is invalid.", LogType.ERROR);
            }
        }
        else
        {
            Logger.LogFile(fid, "fail to save file to server. output file path is null or empty.", LogType.ERROR);
        }

    }

                document = new RasterEdge.XDoc.PDF.PDFDocument(documentPath);

                string paraFilepathValue = docinfo.GetRequestParameters("yourtarget");