MVC Html.ActionLink removes empty querystring parameter from URL

问题

I'm using the Html.ActionLink(string linkText, string actionName, object routeValues) overload to send some params to an Action Method..

Sometimes I need to pass an empty parameter value like: ?item1=&item2=value

I'm specifying the param in the anonymous type I create and pass as routeValues, but both null and string.Empty result in a URL that omits the empty item1 param.

new { item1 = null, item2 = "value" } 
new { item1 = string.Empty, item2 = "value" }
new { item1 = "", item2 = "value" }

// all result in:
?item2=value

I can create the URL manually but I want to use the helper method.

Suggestions?

回答1:

Create an EmptyParameter class as follows:

public class EmptyParameter
{
    public override string ToString()
    {
        return String.Empty;
    }
}

Then:

@Html.ActionLink("Action",
                 "Controller",
                  new { item1 = new EmptyParameter(), item2 = "value" });

来源：https://stackoverflow.com/questions/17702203/mvc-html-actionlink-removes-empty-querystring-parameter-from-url