How do I render and return a view as pdf

Question

So I'm trying to add a new endpoint to my controller which can return the html response of another endpoint at pdf. The reason for this is deprecate a 3rd party service which involves all kinds of other problems.

I've found a library called IronPDF which seems to do the job, but I'm now struggling to get the html of the original endpoint. It looks something like this:

public class HomeController : Controller
{
    public HomeController() : base() { }

    public IActionResult Index()
    {
        return View();
    }
    
    public IActionResult IndexPdf()
    {
        ViewResult view = Index() as ViewResult;
        HtmlToPdf renderer = new HtmlToPdf();

        // How do I get the html content of view as a string here?
        string html = ??

        PdfDocument pdf = renderer.RenderHtmlAsPdf(html);
        
        using (var stream = pdf.Stream)
        {
            return File(stream, "application/pdf", "Index.pdf");
        }
    }
}

How do I get the html of the ViewResult?

This is just an example, I'm hoping to adapt it to handle dynamic pages in future. Is there a better way of doing this?

Ruikai Feng · Answer 1 · 2023-07-13T05:42:35.943

You could try as below in your controller:

public async Task<IActionResult> IndexPdf()
    {
        using StringWriter sw = new StringWriter();
        IView view = _viewEngine.FindView(ControllerContext, "Index",true).View??default!;
        ViewContext viewContext = new ViewContext(ControllerContext, view, ViewData, TempData, sw, new HtmlHelperOptions());
        await view.RenderAsync(viewContext);
        var content = sw.GetStringBuilder().ToString();

        ChromePdfRenderer renderer = new ChromePdfRenderer();

        PdfDocument pdf = renderer.RenderHtmlAsPdf(content);
        return File(pdf.Stream, "application/pdf", "Index.pdf");
        

    }

inject ICompositeViewEngine into your controller:

private readonly ICompositeViewEngine _viewEngine;

        public HomeController(ILogger<HomeController> logger, ICompositeViewEngine viewEngine)
        {
            .......
            _viewEngine = viewEngine;
        }

Result:

Notice:

1,HtmlToPdf is obsolote,you could try with ChromePdfRenderer

2,You have to input full address for your css files,or the css won't work

the content string is OK,I checked with return Ok(content):

3,You could just try with

renderer.RenderUrlAsPdfAsync("targeturl");

directly,without getting the html of the ViewResult.

How do I render and return a view as pdf

1 Answers1