How to return link to file in ASP Net Core? - asp.net-core

Question

I do not know how to serve links to files in ASP Net Core.I have tried using the PhyisicalFileProvider class to no avail.
What i want
Given a folder root on the hard disk , on receiving a querystring
like : /localFolder/test.txt i want the server to send a Link so
the user can click and get the file test.txt
Important
I do not want to send the file but a link to it , so he can click it and download it.
What i have tried:
1.Using the extension method IApplicationBuilder.Map in order to direct the requests directly to the file.
2.Using the extension method IApplicationBuilder.Map + Adding a middleware ,though i do not know how to i serve the link ? (add it
in the response body?)
Startup
public void ConfigureServices(IServiceCollection collection)
{
//i have also added the provider to the service collection to further inject it in the middleware
var phyisicalFileProvider = new PhysicalFileProvider(config.Storage.DocxFileRoot);
services.AddSingleton<IFileProvider>(phyisicalFileProvider);
}
public void Configure()
{
//scenario without middleware
app.Map("/localfiles", x =>
x.UseStaticFiles(new StaticFileOptions {
FileProvider = new PhysicalFileProvider([some file root]),RequestPath ="/localfiles"}
));
//scenario with middleware
app.Map("/localfiles",x=>
x.UseMiddleware<FileWare>()
);
app.UseEndpoints(endpoints => {
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=File}/{action=Index}/{id?}");
});
}
Middleware
public class FileWare
{
private IFileProvider provider;
private RequestDelegate next;
public FileWare(RequestDelegate next,IFileProvider provider)
{
this.provider=provider;
this.next=next;
}
public async Task Invoke(HttpContext context)
{
var query = context.Request.Query;
var path=query.First(x => x.Key == "path").Value;
var fileInfo=this.provider.GetFileInfo(path);
await fileInfo.CreateReadStream().CopyToAsync(context.Response.Body);
}
}

Answer 1

If you just want to have a link in razor view,click the link to download a file in the local disk(for example C:\MyFolder), you could follow below steps:
1.Razor View
<a asp-controller="File" asp-action="download" asp-route-path="C:\MyFolder\test.txt">Download</a>
2.FileController
public IActionResult Download([FromQuery]string path)
{
string fileName = "test.txt";
byte[] fileBytes = System.IO.File.ReadAllBytes(path);
return File(fileBytes, "application/force-download", fileName);
}

Answer 2

Code below helps to serve files to users in ASP NET Core:
in program.cs write this:
app.UseStaticFiles(new StaticFileOptions
{
FileProvider = new PhysicalFileProvider(
Path.Combine(builder.Environment.ContentRootPath, "RealFilePath")),
RequestPath = "/NickNameForPath"
});
then in yourpage.cshtml, code this link:
Get File
And do not forget place folders under wwwroot