Blazor: How to pass multiple parameter's from NavigateTo to a WEB API controller to download a file

Question

I'm trying to use NavivgateTo in Blazor to pass a file id and name to download a file from my Download controller.

What is the proper setup? I've tried a number of possibilities and I keep seeing an error: Sorry, there is nothing at this address.

Razor Page

        public async Task SelectedDisplayDbItemChanged(DisplayDbItemsComboBoxItemDTO item)
        {
            Data = null;
            
            Data = GetDataTable();

            var fileId = await utilities.ExportDataTableToFile((DataTable)Data).ConfigureAwait(false);
            //navigationManager.NavigateTo($"api/download/fileId/" + fileId + "/fileName/" + "myfile", true);
            //?data1=678&data2=c-sharpcorner
            navigationManager.NavigateTo($"api/Download/{fileId}/{"myfile"}", true);
        }

Controller:

        [HttpPost("Download/{fileId}/{fileName}")]
        public async Task<IActionResult> Download(string fileId, string fileName)
        {
            using (var ms = new MemoryStream())
            {
                var fullPath = Path.Combine(DownloadPath, fileId);
                await using (var stream = new FileStream(fullPath, FileMode.Open))
                {
                    await stream.CopyToAsync(ms);
                }
                ms.Position = 0;
                return File(ms, "application/octet-stream", $"{fileName}.xlsx");
            }
        }

I've seen a lot of examples from the Razor page to the Razor page, but not from NavigateTo to a controller with passing multiple parameters.

I've tried these responses as well: https://stackoverflow.com/a/71130256/9594249 https://stackoverflow.com/a/71130256/9594249

Stardog · Accepted Answer · 2022-06-14T00:42:03.343

Not like Asp.net MVC or razor page, in Blazor parameters are passed by [Parameter] tag

@page "/Download/{fileId}/{fileName}"
@code {
    [Parameter]
    public string? fileId { get; set; }
    [Parameter]
    public string? fileName { get; set; }
}

please refer : https://learn.microsoft.com/en-us/aspnet/core/blazor/fundamentals/routing?view=aspnetcore-6.0

(Updated)

add to Program.cs or Startup.cs:

builder.Services.AddRazorPages(options => {
    options.Conventions.AddPageRoute("/DownloadPage", "Download/{fileId?}/{fileName?}");
    }
});

Pages/DownloadPage.cshtml

@page "{fileId?}/{fileName?}"
@model BlazorApp.Pages.DownloadModel

Pages/DownloadPage.cshtml.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;

namespace BlazorApp.Pages;

    public class DownloadModel : PageModel
    {
         private readonly IWebHostEnvironment _env;
    
         public DownloadModel(IWebHostEnvironment env)
         {
             _env = env;
         }
        public IActionResult OnGet()
        {
            // work with RouteData.Values["fileId"] and RouteData.Values["fileName"]
        }
    }

please refer :

https://learn.microsoft.com/en-us/answers/questions/243420/blazor-server-app-downlaod-files-from-server.html

https://learn.microsoft.com/ko-kr/aspnet/core/razor-pages/razor-pages-conventions?view=aspnetcore-6.0

This is calling a web api controller from within Blazor. Maybe I'm doing it all wrong (new to Blazor), but I need to open up another tab to download a file. My controller to download the file works good if I add in a static file id, file name. — tvb108108, Jun 13 '22 at 09:47
Ah, now I see the point now. Blazor has no controller like ASP.net MVC so it will be complicated to do so and I think you have to work with startup.cs or program.cs. I'll update my answer. — Stardog, Jun 14 '22 at 00:13

Blazor: How to pass multiple parameter's from NavigateTo to a WEB API controller to download a file

1 Answers1