C＃中的JavaScript

Question

<script>
 ...

   var Klasa = calEvent.ClassID;
   @{
     var NameOfClass = Model.FirstOrDefault(xx => xx.ClassID == @:Klasa).Nazwa_Klasy;
   }

  $description.append($('<p/>').html('<b>Klasa:</b>' + @NameOfClass

 ...
</script>

How should I correct mix JS with C#?

I get information 'Cannot use local variable "NameOfClass" before it is declared',

but when I declare variable again before with string value then I get 'An opening "(" is missing the corresponding closing ")"' and then I am not sure what exactly I should do, because everything looks all right.

My main target is that I want to get single data from Model (Nazwa_Klasy) where ClassID is equal calEvent.ClassID. Maybe should I also change my expression?

Thanks for any answer!

Answer 1

First of all, let's clarify few things:

This will be var Klasa = calEvent.ClassID; happening on the client side. Means, some action will cause calEvent in the browser. If yes , then it makes following pointless.

Model.FirstOrDefault(xx => xx.ClassID == @:Klasa)

As on the server (where this is run), klasa is not available. So your best bet is to spit Model , which seems to be an array on the client side and then filter that. Don't know if I'm making any sense, but do give following a try:

<script>
    ...
    //Array of object to look into at client side
    var modelArray=@Html.Raw(JsonConvert.SerializeObject(Model));
    var Klasa = calEvent.ClassID;

    var NameOfClass=null;
    $.each(modelArray,function(){
        if($(this).ClassID===klasa){
            NameOfClass = $(this).Nazwa_Klasy;
            return;
        }
    });

    //You may want to test if `NameOfClass` has a value.
    $description.append($('<p/>').html('<b>Klasa:</b>' + NameOfClass
 ...
</script>

Also, as pointed out in comments, @:klasa is wrong. You don't need : there.

Answer 2

@TheVillageIdiot the way of Your thinking was good, but the code didn't work properly as I wanted. So, I changed it a little to

     var modelArray = @Html.Raw(JsonConvert.SerializeObject(Model));
                var Klasa = calEvent.ClassID;


                for (var i = 0; i < modelArray.length; i++) {
                    var obj = modelArray[i];
                    if (obj.ClassID === Klasa) {
                        NameOfClass = obj.Nazwa_Klasy.trim();
                    }
                }


                $description.append($('<p/>').html('<b>Klasa: </b>' + NameOfClass));

Right now everything is fine.

Thanks a lot! ;-)

Answer 3

This may not be the quick answer to your question, but there's a live demo addressing the issue of working with JavaScript inside ASP.NET MVC apps this week. It's on Oct 26 and I'm sure there will be a recording afterwards if you can't attend. This is the registration page. - you can also ask your questions there.