CheckBoxList Helper extension method ASP.NET MVC 3

Here’s a quick and dirty html helper for checkboxes in ASP.NET MVC 3. I’m sure Microsoft will eventually package one with the MVC framework just like they will a radiobuttonlist helper, but in the meantime, this one suits my purposes.

Of course, from a front-end point of view, a multi-select listbox is also an option, but checkboxes are a little more robust when it comes to user interaction. Nothing is more annoying as a user than forgetting to ctrl-click and having all your previous selections disappear.

You can probably find variations around, most that I’ve seen use a generic list of a custom class – mine uses a MultiSelectList instead, just for fun.

public static class NSCheckboxListExtensions
        public static MvcHtmlString CheckboxListFor<TModel, TProperty>(
                    this HtmlHelper<TModel> htmlHelper,
                    Expression<Func<TModel, TProperty>> expression,
                    MultiSelectList listOfValues)
            var metaData = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
            var sb = new StringBuilder();

            if (listOfValues != null)
                foreach (var item in listOfValues)
                    var id = string.Format("{0}_{1}", htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(expression)), item.Value);
                    var name = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(expression));
                    var label = htmlHelper.Label(id, HttpUtility.HtmlEncode(item.Text));

                    var cb = new TagBuilder("input");
                    cb.MergeAttribute("type", "checkbox");
                    cb.MergeAttribute("name", name);
                    cb.MergeAttribute("value", @item.Value);
                    cb.MergeAttribute("id", id);
                    if (@item.Selected)
                        cb.MergeAttribute("checked", "checked");
                    sb.AppendFormat("{0}{1}</br>", cb, label);
            return MvcHtmlString.Create(sb.ToString());

2 thoughts on “CheckBoxList Helper extension method ASP.NET MVC 3”

  1. Nice extension. One small issue: ” is not a valid tag. I assume you meant ” instead.


  2. Very nice example. I used this with an extension method to create a multi-column checkbox list.
    I had searched through many, many sites looking for someone who demonstrated a grasp of the problem and application.
    Thank you.

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