QuestPDF have a Previewer option before generating PDF - c#

We have to view PDFs before generating the PDF file. We have tried adding the below-mentioned code but it's not working for us in WinForm and our application gets freezed.
using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;
// code in your main method
var document = Document.Create(container =>
{
container.Page(page =>
{
// page content
});
});
// instead of the standard way of generating a PDF file
document.GeneratePdf("hello.pdf");
// use the following invocation
document.ShowInPreviewer();
// optionally, you can specify an HTTP port to communicate with the previewer host (default is 12500)
document.ShowInPreviewer(12345);
Is it possible for QuestPDF to view PDF before generating the file?

Related

How do I download a page with Selenium

I did not find a solution how to download a whole Webpage
All I want is to navigate to https://api.tracker.gg/api/v2/rocket-league/standard/profile/epic/ManuelNotManni?
and download it. Is it possible to download the page with Selenium?
I used the following Code to navigate to the page:
var options = new ChromeOptions();
using (var driver = new ChromeDriver(".", options))
{
driver.Navigate().GoToUrl("https://api.tracker.gg/api/v2/rocket-league/standard/profile/epic/ManuelNotManni?");
}
You can retrieve the page source content with driver.PageSource command. And save it to the file.
var options = new ChromeOptions();
using (var driver = new ChromeDriver(".", options))
{
driver.Navigate().GoToUrl("https://api.tracker.gg/api/v2/rocket-league/standard/profile/epic/ManuelNotManni?");
await File.WriteAllTextAsync("PageSource.html", driver.PageSource);
}
For downloading json it will work well.
But for html pages, note:
If the page has been modified after loading (for example, by JavaScript) there is no guarantee that the returned text is that of the modified page. Please consult the documentation of the particular driver being used to determine whether the returned text reflects the current state of the page or the text last sent by the web server. The page source returned is a representation of the underlying DOM: do not expect it to be formatted or escaped in the same way as the response sent from the web server.
References
https://www.selenium.dev/selenium/docs/api/dotnet/html/P_OpenQA_Selenium_IWebDriver_PageSource.htm
https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-write-to-a-text-file

Exporting RDLC on letter head

I have a requirement to export RDLC report into PDF, it should also contain letter head of the company in background. Problem I see is that RDLC has a header, body and footer, how do we apply common image background? Any idea to this issue?
(Posted as an answer, since it's too long for a comment.)
I don't know of a method to add a page background directly in an RDLC. However, we had a similar issue with our report generator (MS Access, not RDLC), and solved it by (1) creating the PDF without letterhead and then (2) using PDFSharp to merge the resulting PDF with a letterhead ("background") PDF. Something like this might work for your use case as well.
We use the following code:
public static void AddBackground(string source, string background, string result)
{
using (var formBackground = XPdfForm.FromFile(background))
using (var pdf = PdfReader.Open(source, PdfDocumentOpenMode.Modify))
{
foreach (var page in pdf.Pages.Cast<PdfPage>())
{
var xg = XGraphics.FromPdfPage(page, XGraphicsPdfPageOptions.Prepend);
xg.DrawImage(formBackground, 0, 0);
if (formBackground.PageIndex < formBackground.PageCount - 1)
{
formBackground.PageIndex += 1;
}
}
pdf.Save(result);
}
}
All parameters are paths to the respective PDF files. If the background PDF has less pages than the source PDF, then the last page of the background PDF is added to all remaining source PDF pages. It is useful if your first page has a different background than all remaining pages, you just need a 2-page background PDF for that.

C# MVC generate PDF from View with NReco.PdfGenerator

I'm currently working on a project where I need to create a "dashboard" which can be exported as pdf. I wanted to use Rotativa but as our application uses .NET framework 4.0 it's not possible. So I found the NReco PdfGenerator.
Now that's the code how I create the PDF result:
var ViewAsString = RenderViewAsString("~/Views/QMetrics/StandardDashboard.cshtml", viewModel);
var htmlToPdf = new NReco.PdfGenerator.HtmlToPdfConverter();
htmlToPdf.PageWidth = 1600;
htmlToPdf.PageHeight = 900;
var pdfBytes = htmlToPdf.GeneratePdf(ViewAsString);
FileResult FileResult = new FileContentResult(pdfBytes, "application/pdf");
FileResult.FileDownloadName = "Dashboard-" + viewModel.ProjectName + "-" +
DateTime.Now.ToString() + "-.pdf";
return FileResult;
It successfully creates the PDF page with all the content that comes from the backend (Project information, and so on) but the page looks very ugly. On the original page I have 2 columns and on the PDF page it puts everything in one column. I tried a few different page sizes and I also changed the layout to be non-responsive but nothing has changed.
My first suggesstion was that the referenced CSS and JS files are not included when the PDF get's created, so I copied all the stuff that comes from external files (bootstrap, Chart.js) and pasted it directly in the .cshtml file. But nothing changed at all. My Chart is not rendering/loading and the missing CSS stuff is still not there.
On the NReco PDFGenerator website they say that it supports complex CSS code and also javascript code so I don't really understand why this is not working.
Has anyone here experiences with NReco or can someone recommend something else that works for .NET 4.0?
NReco PdfGenerator internally uses wkhtmltopdf tool, so you can check it and its options.
Regarding 2 columns: if you don't use flex/grid layout everything should work fine. Possibly you need to disable wkhtmltopdf smart shrinking logic (enabled by default) and define web page 'window' size explicitely (with "--viewport-size 1600" option).
Regarding CSS and charts: you need to check that CSS files could be accessed by wkhtmltopdf, simplest way to do that is running wkhtmltopdf.exe from the command line and check console log output (or, handle PdfGenerator's "LogReceived" event in C#). For Chart.js ensure that chart container div has explicit width (not in %), and that there are no js errors (you can get them in console by specifying "--debug-javascript" option). If your js code uses 'bind' method you have to include polyfill as WebKit engine version used in wkhtmltopdf doesn't support 'bind'.

Using custom template files with bpac API (Brother label printer API) in C#

I designed a layout file using P-touch Editor 5.1 and saved it as P-touch layout(.lbx) file. It is not working in my C# project.
I am unable to set barcode data and the text lable in my C# project while using this layout file.
My problem is to set the attributes in the C# program. How can I find the attributes of the template? The following code is not working:
const string TEMPLATE_DIRECTORY = #"C:\Program Files (x86)\Brother bPAC3 SDK\Templates\newCustomTemplate.lbx";
bpac.DocumentClass doc = new DocumentClass();
if(doc.Open(templatePath) != false)
{
doc.SetBarcodeData(253654789, "Apple iPhone");
//Rest of the code
......
}
The printed lable does not contain the new data. It print the same data as set in the templete at design time.
Any help will be appreciated.
First off, you need to give names to each element you put on the tag in P-touch.
(Right click, last tab). When you are addressing these fields you can use
doc.GetObject("objCompany").Text = txtCompany.Text;
for any fields except for some barcodes (CODE128/EAN128), that you need to address with their index, you can get their index with:
bc = doc.GetBarcodeIndex("barcodename")
then you can use
doc.SetBarcodeData(bc, "Apple iPhone");

Displaying pdf files in a web page from a sql database directly without needing to save them to the server file system

I'm currently using an html embed tag to display a pdf file that is saved on the local server. Is there a wayo to display a pdf file on my page without having to save it to the local file system of the server? I just wand to pass it to the view from the controller in such a way that it can be displayed as a pdf in the page without having it stored on the file system directly.
Alternatively, is there a way to call a method to delete the pdf file from the server once the user has navigated away from the page they are viewing? How do I tell if th euser has navicated away from the page and how do i cause that to trigger a method that will delete the file?
I created a MVC class called PdfResult that returns a byte array as a PDF file.
The purpose is as follows (can't upload the source code, sorry):
PdfResult inherits from FileStreamResult
Set the Content-Type header to application/pdf
Set the Content-Disposition to either attachment or inline, and set an appropriate file name
Convert your data to a Stream -- if your data is a byte array, then write it to a MemoryStream.
See https://stackoverflow.com/a/16673120/272072 for a good example of how to do this.
Then, your embed code just needs to point to the action method, as if it was a PDF file.
Here's an example:
public ActionResult ShowPdf() {
// Note: the view should contain a tag like <embed src='MyController/GetPdf'>
return View();
}
public ActionResult GetPdf() {
byte[] pdfBytes = dataRepo.GetPdf(...);
return new PdfResult(pdfBytes, "Filename.pdf", false) ;
}
Here is a link to a CodeProject article and code sample titled Download and Upload Images from SQL Server via ASP.NET MVC. This gives an example of an efficient method to stream content to and from SQL Server via MVC.
You can easily adapt the code to stream your PDF file downloads.
UPDATE
The article uses a DataReader, but it can easily be adapted to Linq2Sql or EF. As an example, here is the Read method where I am reading from the database and copying to the stream:
public override int Read(byte[] buffer, int offset, int count)
{
result = _attachments.ExecuteStoreQuery<byte[]>(
"SELECT SUBSTRING(AttachmentBytes, " + position.ToString() +
", " + count.ToString() + ") FROM Attachments WHERE Id = {0}",
id).First();
var bytesRead = result.Length;
Buffer.BlockCopy(result, 0, buffer, 0, bytesRead);
position += bytesRead;
return (int)bytesRead;
}
You can read the PDF as a bytestream from the database and save it to the http response stream. If you have set the content type correctly to application/pdf, then the browser will load the document in the PDF plugin.
Update (14/Oct/2011): You need to write the bytestream to the Response.OutputStream object. How you create and write the byte stream is dependent on how you have stored in the database and how you are retrieving it. The following code snippet is from an article we have on our website - Generate PDF Forms In ASP.NET Using PDFOne .NET v3.
// Get the page's output stream ready
Response.Clear();
Response.BufferOutput = true;
// Make the browser display the forms document
// using a PDF plug-in. (If no plug in is available,
// the browser will show the File -> Save As dialog box.
Response.ContentType = "application/pdf";
// Write the forms document to the browser
doc.Save(Response.OutputStream);
doc.Close();
doc.Dispose();
The doc object is from our component. You need not use that. This code snippet is only for your understanding. For your requirement, you may have to something like bytestream.save(Response.OutputStream) I guess. BTW, this code is for ordinary ASP.NET, not MVC.
DISCLAIMER: I work for Gnostice.
If you want to create the PDF 100% dynamically, you would generate it completely in memory then stream it out directly to the requesting web browser without saving it as a file. This is very easy to do with the right tools. I would recommend AspPDF from Persits.com as a way to do this very easily. Take a look at their online documentation to see how simple this is to do without creating a bunch of rendered PDF files all over your server.
If you cannot do something like that, then simply incorporate a process to cleanup your "expired" PDF files from your server's filesystem based on their age. For example, after you have created your local PDF file, you just look through the folder containing your temporary PDF's and delete any you find over a certain age. You cannot reliably tell if or when a user has navigated away from your page or site.
For the first part of your question, like mentioned in the comments, use some type of stream object to pass the PDF data around. Right now, you are streaming the file to the local file system, then streaming it once again to the embedded tag for display. Just do away with the intermediate step of saving to the file system, and do the whole thing in memory (although, that's not really a model of efficiency, and might not scale well).
Regarding the second part of your question, that's not as straightforward. MVC really has no concept of state (viewstate, etc.), so it doesn't have events that can be fired from a state change (say, navigating away from a page).
You could use Javascript to detect a user navigating away from your page (windows.onunload), that calls a (C#/VB) method to remove the file from the file system. You would probably have to use AJAX to communicate back to the server, using an HTTP POST method, and have something listening at that URL endpoint to fire your method that removes the file.

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