Response.Redirect HTTP status code

问题:

Why is it that ASP/ASP.NET Response.Redirect uses a HTTP-302 status code ("Moved Temporarily") even though in most cases a HTTP-301 status code ("Moved Permanently") would be more appropriate?

回答1:

Responses with status 301 are supposed to be cacheable, and I don't think you want that behavior for most ASP/ASP.NET redirects.

ASP.NET 4.0 is has the RedirectPermanent method for that if needed.

回答2:

I've used this handy Permanent Redirect with success:

public void RedirectPermanent(string newPath)
{
  HttpContext.Current.Response.Clear();
  HttpContext.Current.Response.Status = "301 Moved Permanently";
  HttpContext.Current.Response.AddHeader("Location", newPath);
  HttpContext.Current.Response.End();
}

回答3:

One common use case of Response.Redirect is to move the user to another page in server-side code after a postback, e.g. something along the lines of

private void MyButton_Click(object sender, EventArgs e)
{
    if (some condition) {
         Response.Redirect("ShowProduct.aspx");
    } else {
         Response.Redirect("SorryOutOfStock.aspx");
    }
}

In those cases, 301 would be completely wrong. In fact, I think that the above case (conditionally move the user to another page after some UI interaction) is a much more common use of Response.Redirectthan a real this-page-moved-to-another-URL-forever scenario (where a return code of 301 would be appropriate).

回答4:

In addition to the answer from Heinzi, the only entity on the web that is likely to take much notice of the 301 would be the search engines. Most browsers will not track and record 301 in order automatically redirect any subsequent request for the initial URL. Browsers treat 301 identically to how they treat 302. Hence 302 in dynamic content such as generated in ASP.NET is quite appropriate.

回答5:

The error you are getting is not due to response.redirect !

The HTTP response status code 301 Moved Permanently is used for permanent redirection, meaning current links or records using the URL that the 301 Moved Permanently response is received for should be updated to the new URL provided in the Location field of the response.