将值从下拉列表传递给html actionlink mvc4 razor

Question

I am trying to pass a value from a drop down list to an existing link, however nothing seems to work:

index.cshtml:

@Html.ActionLink("Download", "MyDownload", null, new { @class = "button" })  
@Html.DropDownList("schools", "-- All Schools --")  

in my SchoolsController:

public FileContentResult MyDownload(string school="")
{
    List1<>
    List2<>

    var vals = 
         from list1
         join list2
         from
         select new {
             };

    if(school ! ="")
    {
        vals.where(x.list2.schools==school).tolist(); **// I get this error: "Object reference not set to an instance of an object."**
    }    
}

Something I can do easily in other languages, I find learning C# MVC takes forever.

Answer 1

You could use jQuery to monitor the change Event on your dropdownlist. Now, I'm not entirely sure if you're trying to change the text that is used for the link or the actual href of the link. Below I've created some code to change both.

View

$(document).ready(function () {
    $("#schools").change(function () {
        var selection = $("#schools").val();
        var link = $("#Download");

        //Change text
        link.text(selection);

        //Change href
        link.attr("href", "linkHref" + selection)
    });
});

It will look something like this, pending what you're wanting to do with your link and dropdownlist's selection.