Cannot pass data with ajax to razor pages

Question

I am trying to send some data to razor page method, but the problem is that in method it takes always as 0.

Heres the code:

Razor Page:

Answer 1

page is essentially a reserved name when using ASP.NET Core 2.0 Razor Pages. The problem you have is actually quite simple, yet very subtle:

When it sees a query-string parameter, the ASP.NET Core 2.0 Razor Pages framework interprets this as the name of the current Razor Page - You can see that if you change your page parameter to type string; it'll actually contain the name of the current page. In your case, because the type is an int, the model-binding process cannot bind a string (the name) to a number, so sets it to 0.

One way to work around this issue is to use a different name. e.g.:

public IActionResult OnGetProducts(int pageNumber)

-and-

data: {
    pageNumber: page,
    handler: 'Products'
}

There's a fair bit of discussion around this issue on Github, but it's not specific to your scenario. I suggest you either search for or raise a new issue that specifically talks about using a query-string parameter in a Razor Page.

As an unrelated side note, you don't need to set the Content-Type header in your $.ajax request - This is used when you are sending content, which you're not.