Is there a way to concatenate strings in html attributes?

Try this (verified):

<div id="@("label"+Model.Id)" class="display-field">@Model.InitValue</div>

Here is what you need to do.

id="[email protected]"

Underscore(_) is required.For me passing id without Underscore made an issue. Happy conding.

Just adding another option as this is what worked for me when trying to concat string and model value as id in an @html.ActionLink and also for the text value. I needed to use string.Concat. Don't know if this is bad from a performance point of view.

  @Html.ActionLink(string.Concat("View all (", @Model.FooCount, ")"),
        //actionName        
        "SeeAllFoos",
        //ControllerName
        "Foo",
        // routeValues
        new { FooId = @Model.Foo.id },
        //htmlAttributes
        new { @class = "btn btn-success", onclick = "ShowProgress();",
        id = string.Concat("Foo",@Model.Foo.id.ToString()) })

You want:

<div id="[email protected]" ...

Razor will recognise the @ as the start of code, execute it and render the results in place in the attribute.

Edit:

This didn't work well as a comment, but here's a line from one of my Razor controls:

<input type="text" readonly="readonly" 
       class="display-field [email protected]" 
       id="@((ViewData["id"] == null) ? 
         ViewData.ModelMetadata.PropertyName : ViewData["id"])"
       value="@Proj.GetJobStatusValue(Model)" />

Try adding a hyphen (-) before the @. It's quite possible that Razor thinks it's an e-mail address and leaving it alone!