Call razor c# function from javascript function

Question

I have an html link in one file

<a href="#" onClick="xupdate('Home')" id="padlink">Home</a>

On click I want a js function(in another file, with extension js) to execute and that is:

function xupdate(string) {
     document.title = string;
     //Call razor c# function
}

Now I have a c# function(it reads files and displays their information) in a cshtml file:

@helper fileRead(String file) {
            var dataFile = Server.MapPath(file);
            Array userData = File.ReadAllLines(dataFile);
            foreach (string dataLine in userData) {
                foreach (string dataItem in dataLine.Split(',')) {
                    //dataItem <text>&nbsp;</text>
                    @Html.Raw(dataItem);
                 }
             }
}

I want to call the fileRead function from the js xupdate() function and send the value of string into fileRead as a parameter.Is there a way to do this?

Note: I have already included the html link in the cshtml file and my functions work perfectly. Also I know that I have to include a file extension when calling the c# function.

Answer 1

You can not call C# function from javascript directly, Because javascript execute on client side and C# function execute at server side.

So you must call it other way like AJAX.

Define your function in controller and call it via AJAX call.

Answer 2

Use AJAX:

var ret = null;
$.ajax({
   async: false,
   url: "YourFunctionName_in_Controller",
   dataType: "json",
   success: function (data) {ret = data;}
      });
return ret;