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How to disable DropDownList option in asp.net server side?

I have a dropdown to populate the backend, some of the options to be populated in this list need to be disabled. In practice, I know that I need to add the disabled = 'disabled' attribute.

This is the first way I tried.

Dim avListItems = activityVersions.Select(Function(av) New With {.Text = av.Text, .Value = av.Value, .Disabled=av.HasQuota}).ToList()

But this disables all options because no value is needed in the HTML disabled attribute, if there is disabled attribute then it disables the option anyway. But I need a solution that can add a disabled attribute for parameters that have no quota and others must be enabled.

Do you have any suggestions?

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2 answers


Unable to disable individual items in a dropdown list. See MSDN .



Perhaps rather apply some validation to notify the user if an invalid option is selected, or to remove those items entirely from the list.

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It is actually possible to disable the item in the dropdown. you need to bind the list and then add a new attribute to it. The example below provides a list of countries.



List<Country> countryList = CountryFunctions.CreateCountryCollection();

                ddlCountryList.DataSource = countryList;
                ddlCountryList.DataTextField = "Name";
                ddlCountryList.DataValueField = "Code";
                ddlCountryList.DataBind();

                //Disable any preselected items in dropdown list
                foreach (var country in countryList)
                {
                    var disabledCountry = IsCountryDisabled(country.Code);

                    if (country.Id != 0)
                    {
                        ddlCountryList.Items.FindByValue(country.Code).Attributes.Add("disabled", "true");
                    }
                }
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