I have a project ASP.NET Core 2.0 MVC running on IIS.
Want to Export some information from data grid to Excel and save it from web page to the desktop of current user.
string fileName = "SN-export-" + DateTime.Now + ".xlsx";
Regex rgx = new Regex("[^a-zA-Z0-9 -]");
fileName = rgx.Replace(fileName, ".");
string path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
string fileName2 = Path.Combine(path, fileName);
FileInfo excelFile = new FileInfo(fileName2);
excel.SaveAs(excelFile);
This works perfect local at Visual Studio, but not after publishing at IIS.
Using simple path string path = #"C:\WINDOWS\TEMP"; It will save this export file at the server temp folder, but not current web page user.
How to get this?
ASP.NET MVC is framework for a web application. So you have fronted and backend parts. This code will executed on the server side of your application. Even if you use Razor pages, they also generated at the backend. So there are several ways to save data on the computer:
use js to iterate data and save it, but I'm not sure that saving to excel with js is easy;
send desired data to backend, save it to excel and then return to the client.
For a second way you can use next code:
[Route("api/[controller]")]
public class DownloadController : Controller {
//GET api/download/12345abc
[HttpGet("{id}"]
public async Task<IActionResult> Download(YourData data) {
Stream stream = await {{__get_stream_based_on_your_data__}}
if(stream == null)
return NotFound();
return File(stream, "application/octet-stream"); // returns a FileStreamResult
}
}
And because of security reasons you can save data only to downloads directory.
Related
I am not sure what is happening here.
When I run my web application locally and click a button to download a file, the file is downloaded fine and Response header as you can see in the attached screenshot where it says local.
But when I publish the application to azure web app. Somehow the download button stops working. I checked the Response Header and you can see the difference.
What would cause this problem? The code is the same? Is there any settings that I should be setting in azure web app in azure portal?
Updated to add code
I have debugged remotely to figure out what is going on as #Amor suggested.
It is so strange that When I debug on my local machine first ExportTo action gets hit which prepares the TempData then Download action gets called once the first action completed with ajax call.
However, this is not the case when I debug remotely. Somehow the ExportTo action never gets called. It directly calls the Download action. As a result the TempData null checking is always null.
But why? Why on earth and how that is possible? Is there something cached somewhere?
I have wiped the content of web application on the remote and re-publish evertyhing to ensure everything is updated. But still no success.
here is the code:
[HttpPost]
public virtual ActionResult ExportTo(SearchVm searchVm)
{
var data = _companyService.GetCompanieBySearchTerm(searchVm).Take(150).ToList();
string handle = Guid.NewGuid().ToString();
TempData[handle] = data;
var fileName = $"C-{handle}.xlsx";
var locationUrl = Url.Action("Download", new { fileGuid = handle, fileName });
var downloadUrl = Url.Action("Download");
return Json(new { success = true, locationUrl, guid = handle, downloadUrl }, JsonRequestBehavior.AllowGet);
}
[HttpGet]
public ActionResult Download(string fileGuid, string fileName)
{
if (TempData[fileGuid] != null)
{
var fileNameSafe = $"C-{fileGuid}.xlsx";
var data = TempData[fileGuid] as List<Company>;
using (MemoryStream ms = new MemoryStream())
{
GridViewExtension.WriteXlsx(GetGridSettings(fileNameSafe), data, ms);
MVCxSpreadsheet mySpreadsheet = new MVCxSpreadsheet();
ms.Position = 0;
mySpreadsheet.Open("myDoc", DocumentFormat.Xlsx, () =>
{
return ms;
});
mySpreadsheet.Document.Worksheets.Insert(0);
var image = Server.MapPath("~/images/logo.png");
var worksheet = mySpreadsheet.Document.Worksheets[0];
worksheet.Name = "Logo";
worksheet.Pictures.AddPicture(image, worksheet.Cells[0, 0]);
byte[] result = mySpreadsheet.SaveCopy(DocumentFormat.Xlsx);
DocumentManager.CloseDocument("myDoc");
Response.Clear();
//Response.AppendHeader("Set-Cookie", "fileDownload=true; path=/");
Response.ContentType = "application/force-download";
Response.AddHeader("content-disposition", $"attachment; filename={fileNameSafe}");
Response.BinaryWrite(result);
Response.End();
}
}
return new EmptyResult();
}
here is the javascript:
var exportData = function (urlExport) {
console.log('Export to link in searchController: ' + urlExport);
ExportButton.SetEnabled(false);
var objData = new Object();
var filterData = companyFilterData(objData);
console.log(filterData);
$.post(urlExport, filterData)
.done(function (data) {
console.log(data.locationUrl);
window.location.href = data.locationUrl;
});
};
When Export button is clicked exportData function is called:
var exportToLink = '#Url.Action("ExportTo")';
console.log('Export to link in index: '+exportToLink);
SearchController.exportData(exportToLink);
As I mentioned that this code works perfectly on the local machine. something weird is happening on azure webapp that ExportTo action breakpoint is never gets hit.
I am not sure what else I could change to get the ExportTo action hit?
Based on the Response Header of Azure Web App, we find that the value of Content-Length is 0. It means that no data has been sent from web app server side.
In ASP.NET MVC, we can response file using following ways.
The first way, send the file which hosted on server. For this way, please check whether the excel file has been uploaded to Azure Web App. You could use Kudu or FTP to the folder to check whether the file is exist.
string fileLocation = Server.MapPath("~/Content/myfile.xlsx");
string contentType = System.Net.Mime.MediaTypeNames.Application.Octet;
string fileName = "file.xlsx";
return File(fileLocation, contentType, fileName);
The second way, we can read the file from any location(database, server or azure storage) and send the file content to client side. For this way, please check whether the file has been read successfully. You can remote debug your azure web app to check whether the file content hasn't been read in the right way.
byte[] fileContent = GetFileContent();
string contentType = System.Net.Mime.MediaTypeNames.Application.Octet;
string fileName = "file.xlsx";
return File(fileContent, contentType, fileName);
5/27/2017 Update
Somehow the ExportTo action never gets called. It directly calls the Download action. As a result the TempData null checking is always null.
How many instances does your Web App assigned? If your Web App have multi instances, the ExportTo request is handled by one instance and the Download request is handled by another instance. Since the TempData is store in memory of dedicated instance, it can't be got from another instance. According to the remote debug document. I find out the reason why the ExportTo action never gets called.
If you do have multiple web server instances, when you attach to the debugger you'll get a random instance, and you have no way to ensure that subsequent browser requests will go to that instance.
To solve this issue, I suggest you response the data directly from the ExportTo action or save the temp data in Azure blob storage which can't be accessed from multi instances.
Silly question but here goes...
Is it possible to write an intranet windows auth asp.net mvc app that uses File.Move to rename a file on a users machine? Or will the File.Move and using Path.GetDirectory and other System.IO functions look on the IIS server directory structure instead of the client machine?
[HttpPost]
public ActionResult Index(HttpPostedFileBase file, string append)
{
try
{
if (file != null && file.ContentLength > 0)
{
var fileName = Path.GetFileName(file.FileName);
DirectoryInfo filepath = new DirectoryInfo(file.FileName);
string parentpath = Path.GetDirectoryName(filepath.FullName);
DirectoryInfo searchablePath = new DirectoryInfo(parentpath);
var directories = searchablePath.GetFiles("*", SearchOption.AllDirectories);
foreach (FileInfo d in directories)
{
if (!string.IsNullOrEmpty(append) && !d.Name.Contains(append))
{
string fName = Path.GetFileNameWithoutExtension(d.Name);
string fExt = Path.GetExtension(d.Name);
System.IO.File.Move(d.FullName, Path.Combine(d.DirectoryName, fName + append + fExt));
}
}
}
}
catch (Exception ex)
{
}
return View();
}
I have tried this but am getting a filenotfoundexception.
Any ideas?
The ASP.NET code runs on the server, so it will look at the files on the server.
You can't rename a file on the client machine, however it would be possible to rename a file on the computer that is used as client, if:
the server and computer are on the same network
the server knows the name of the computer
the server knows which folder to look for in the computer
the folder is shared with the user account running the ASP.NET code on the server with enough privileges to change the name of a file
In that sense the computer is not a client to the server, but the server communicates directly with the computer via the file system, not via IIS.
These will indeed work only on the server.
You may look at the various file and filesystem related specifications for client-side javascript APIs provided by the user's browser:
http://www.w3.org/TR/FileAPI/
http://www.w3.org/TR/file-system-api/
http://www.w3.org/TR/file-writer-api/
I have asp.net MVC app in c# and I get query results(from Entity Framework) and I need to put the data in Excel sheet which user can download. So this is what I am trying to do and I want to know how to write each row of data into excel sheet? Any other approach I should take is welcome too.
var certs = CertificateService.ReadAllSentCertificates();
Application excel = new Application();
string filePath = "C:/ToDoList/SentStats_" + DateTime.Now.ToString() + ".xls";
Workbook mybook = excel.Workbooks.Add();
excel.Visible = true;
try
{
mybook.Activate();
Worksheet mysheet = mybook.Worksheets.Add();
foreach (var x in certs)
{
// How to write each row in excel??
}
//mybook.SaveAs(Filename: filepath);
mybook.Save();
}
catch (Exception ex)
{
}
finally
{
mybook.Close();
}
Don't use Office interop in a web application. MS Office was never designed to run on a server. If you want to build an Excel sheet you could use OpenXML on the server.
As an alternative you could return a view containing the results in a <table> and serve this view with the application/vnd.ms-excel Content-Type response header. You will have far less control over the formatting of the resulting sheet compared to using the OpenXML SDK which gives you full control.
I am trying to upload files to a folder from the admin side like a CMS.
The front-end will display links to download the file.
On the admin end, I would like to not only delete the reference to but also remove the actual file from the server.
Here is the part of my controller that saves the uploaded file:
[HttpPost]
public ActionResult Upload(HttpPostedFileBase file)
{
if (file != null && file.ContentLength > 0)
{
var fileName = Path.GetFileName(file.FileName);
var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
file.SaveAs(path);
ViewBag.fileName = fileName.ToString();
return RedirectToAction("Create", new {fileName = fileName });
}
return RedirectToAction("Index");
}
In the Create view, the admin is then allowed to enter other details about the document and that is stored on a table along with the fileName.
Now I need to be able to link to that document name like document.pdf. Am I even able to link to an uploads folder under App_Data folder?
Also, how do I remove the file and not just the table row on doing delete?
Create a separate controller to handle the downloading of the file. It also prevents your users to hotlink directly to the files.
public ActionResult GetDocument(String pathName)
{
try
{
Byte[] buffer = DownloadMyFileFromSomeWhere(pathName);
FileContentResult result = new FileContentResult(buffer, "PDF"); // or whatever file ext
// these next two lines are optional
String[] folders = pathName.Split(new char[] { '\\' }, StringSplitOptions.RemoveEmptyEntries);
result.FileDownloadName = folders[folders.Length - 1];
return result;
}
catch (Exception ex)
{
// log the error or something
}
return new HttpNotFoundResult();
}
Where DownloadMyFileFromSomeWhere(string) should be able to retrieve the byte-array file from some storage like a blob or even the local server. It can look something like:
private Byte[] DownloadMyFileFromSomeWhere(string pathname)
{
Byte[] file = System.IO.File.ReadAllBytes(Server.MapPath(pathname));
return file;
}
For the Admin side, you can do the same approach: Write a separate controller to delete the file and its entry in the database.
Some notes:
If you have rights to save a file somewhere, you should also have the rights to delete it. You can use normal file operations to do this.
IIS should block you from linking to a file under App_Data. You have a couple of options:
Create an action that reads the file from that location and streams it back to the browser
Store in a different location - somewhere that the user will actually have access to.
The benefit of the first option is that you can easily add authentication, etc. to your action to secure access to the files, whereas the second option would require you to add a web.config in the folder with the appropriate roles and access rights. However, on the other hand, you'll have to supply appropriate headers in your action method so the browser knows what to do with the file, rather than letting IIS figure it out for you.
I have an ASP.NET MVC2 application in development and I am having problems rendering a .pdf file from our production server.
On my Visual Studio 2010 integrated development server everything works fine, but after I publish the application to the production server, it breaks. It does not throw any exceptions or errors of any kind, it simply does not show the file.
Here's my function for displaying the PDF document:
public static void PrintExt(byte[] FileToShow, String TempFileName,
String Extension)
{
String ReportPath = Path.GetTempFileName() + '.' + Extension;
BinaryWriter bwriter =
new BinaryWriter(System.IO.File.Open(ReportPath, FileMode.Create));
bwriter.Write(FileToShow);
bwriter.Close();
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.FileName = ReportPath;
p.StartInfo.UseShellExecute = true;
p.Start();
}
My production server is running Windows Server 2008 and IIS 7.
You cannot expect opening the default program associated with PDF file browsing on the server. Try returning the file into the response stream which will effectively open it on the client machine:
public ActionResult ShowPdf()
{
byte[] fileToShow = FetchPdfFile();
return File(fileToShow, "application/pdf", "report.pdf");
}
And now navigate to /somecontroller/showPdf. If you want the PDF opening inside the browser instead of showing the download dialog you may try adding the following to the controller action before returning:
Response.AddHeader("Content-Disposition", "attachment; filename=report.pdf");
i suggest you use ASP.NET MVC FileResult Class to display the PDF.
see http://msdn.microsoft.com/en-us/library/system.web.mvc.fileresult.aspx
your code open`s the PDF on the webserver.
Here's how I did it.
public ActionResult PrintPDF(byte[] FileToShow, String TempFileName, String Extension)
{
String ReportPath = Path.GetTempFileName() + '.' + Extension;
BinaryWriter bwriter = new BinaryWriter(System.IO.File.Open(ReportPath, FileMode.Create));
bwriter.Write(FileToShow);
bwriter.Close();
return base.File(FileToShow, "application/pdf");
}
Thank you all for your efforts. Solution I used is the most similar to the Darin's one (almost the same, but his is prettier :D), so I will accept his solution.
Vote up for all of you folks (both for answers and comments)
Thanks