Disable inclusion of a drop-down list based on model property in mvc

Question

I am trying to disable or enable dropdownlistfor in my mvc application based on a model property: -

What am I doing: -

@Html.DropDownListFor(m => m.ParentOrganisationID, new SelectList(Model.ParentOrganisations, "ID", "Name", Model.ParentOrganisationID), new { @id = "ddlParentOrganisations", @class = "form-control css-select", @disabled = Model.IsReadOnly ? "disabled" : "false", @style = "width:40%; height:10%;" })

but even if the model property "model.IsReadOnly" is false, then the dropdown menu is also displayed as disabled.

Please suggest how to handle this without using javascript

Thanks in advance

Answer 1

(/ ()) DropDownListFor, # ( if), html. SELECT.

<select disabled></select>
<select disabled="disabled"></select>
<select disabled="false"></select>
<select disabled="no"></select>
<select disabled="usingJqueryEnablePlugin"></select>
<select disabled="enabled"></select>

Model if .

@if (!Model.IsReadOnly)
{
    @Html.DropDownListFor(s => s.ParentOrganisationID, 
                               new SelectList(Model.ParentOrganisations, "ID", "Name"))
}
else
{
    @Html.DropDownListFor(s => s.ParentOrganisationID, 
       new SelectList(Model.ParentOrganisations, "ID", "Name"),new {disabled="disabled"})
}

html--, if.

public static class DropDownHelper
{
    public static MvcHtmlString MyDropDownListFor<TModel, TProperty>
                 (this HtmlHelper<TModel> htmlHelper, 
                  Expression<Func<TModel, TProperty>> expression,
                  IEnumerable<SelectListItem> selectItems,
                  object htmlAttributes,
                  bool isDisabled = false)
    {
        ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression,
                                                                    htmlHelper.ViewData);

        IEnumerable<SelectListItem> items =
            selectItems.Select(value => new SelectListItem
            {
                Text = value.Text,
                Value = value.Value,
                Selected = value.Equals(metadata.Model)
            });
        var attributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
        if (isDisabled && !attributes.ContainsKey("disabled"))
        {
             attributes.Add("disabled", "disabled");
        }
        return htmlHelper.DropDownListFor(expression,items, attributes);
    }
}

@Html.MyDropDownListFor(s=>s.ParentOrganisationID,
               new SelectList(Model.ParentOrganisations, "ID", "Name")
                                           ,new { @class="myClass"},Model.IsReadOnly)

Answer 2

HTML: disabled ( ) .

, , HTML DropDownListFor.

. .

Answer 3

Shyju . , HTML5 - * ? MVC DropDownListFor , (_) (-). , .

Here is a special helper that will provide an option to disable DropDownList, and also convert HTML5 - * attributes accordingly . It also saves any other values ​​passed through the htmlAttributes parameter . The code is also a bit more concise (imo).

    public static MvcHtmlString MyDropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> list, string optionLabel, object htmlAttributes, bool disabled)
    {
        var routeValues = new System.Web.Routing.RouteValueDictionary();

        // convert underscores to dashes...
        foreach (System.ComponentModel.PropertyDescriptor property in System.ComponentModel.TypeDescriptor.GetProperties(htmlAttributes))
        {
            routeValues.Add(property.Name.Replace('_', '-'), property.GetValue(htmlAttributes));
        }

        if(disabled)
        {
            routeValues.Add("disabled", "disabled");
        }

        return htmlHelper.DropDownListFor(expression, list, optionLabel, routeValues);
    }

And the markup:

@Html.MyDropDownListFor(m => m.MonthId, Model.Months, "Select Month", new { @class = "form-control", data_url = Url.Action("GetMonths") }, Model.IsDisabled)

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