How to organize multilingual URLs in ASP.Net Core Razor Pages?

You need to build your application considering globalization/localization.

Here is the official documentation from Microsoft.

You may find this tutorial for Developing Multicultural Web Application helpful, it is for DotNetCore 2.1 Razor Pages, but it is valid for 2.2 as well.

Additionally, her is a sample project for localizing razor pages in GitHub

I too was looking for a solution to have translated URLs in razor pages. I ended up with writing a small PageRouteModelConvention.

public class LocalRoute
{
    public string Page { get; set; }
    public List<string> Versions { get; set; }
}

public class LocalizedPageRouteModelConvention() : IPageRouteModelConvention
{
    private static List<LocalRoute> _routes =
    [
        new LocalRoute
        {
            Page = "/Pages/Matches.cshtml", //@page "/Matches"
            Versions = ["kamper"]
        },

        new LocalRoute
        {
            Page = "/Pages/Match.cshtml", //@page "/Match/{slug}"
            Versions = ["kamp/{slug}"]
        }
    ];
    
    public void Apply(PageRouteModel model)
    {
        var route = _routes.FirstOrDefault(p => p.Page == model.RelativePath);
        
        if (route == null) 
            return;
        
        //Clear default route, remove this if needed
        model.Selectors.Clear();
            
        foreach (var option in route.Versions)
        {
            model.Selectors.Add(new SelectorModel()
            {
                AttributeRouteModel = new AttributeRouteModel
                {
                    Template = option,
                }
            });
        }
    }
}

And updated my Program.cs:

builder.Services.AddRazorPages().AddRazorPagesOptions(options =>
{
    options.Conventions.Add(new LocalizedPageRouteModelConvention());
});