ASP.NET

dropdown list default value RSS

6 replies

Last post May 15, 2012 12:46 PM by Doctor Sid

‹ Previous Thread|Next Thread ›

- Reply
EnenDaveyBoy

Participant

1466 Points

1157 Posts

dropdown list default value

May 09, 2012 02:07 PM|LINK

I have a mode which has a int? value

and I have a dropdown list which looks something like

@Html.DropDownListFor(model => model.ChildItems[i].RestrictionValue,
                                                               from Project.Core.Enums.Items.Restriction state in Enum.GetValues(typeof(Project.Core.Enums.Items.Restriction))
                                                               select new SelectListItem() { Text = state.ToString(), Value = ((int)state).ToString() }
                                                         ,"Select", Model.ChildItems[i].RestrictionValue
                                        )

but when there is no value select I get the error

Nullable object must have a value.

is there a way that the selected field can have a 0 value? or is there another work arround
- Edited by enendaveyboy on May 09, 2012 02:11 PM
- Reply
abdu292

Participant

1555 Points

372 Posts

Re: dropdown list default value

May 09, 2012 02:30 PM|LINK

use .value property for the nullable value.

eg.

int? StateID;

then use

StateID.Value;

Don't forget to "Mark As Answer" if a post helps you.

With best regards,
- Reply
EnenDaveyBoy

Participant

1466 Points

1157 Posts

Re: dropdown list default value

May 09, 2012 05:38 PM|LINK

sorry I am a bit lost can you show me what you mean
- Reply
Young Yang -...

All-Star

21742 Points

1825 Posts

Microsoft

Re: dropdown list default value

May 15, 2012 09:35 AM|LINK

Hi

Whick value is int? ? Could you explain more?

Regards
Young Yang

Please mark the replies as answers if they help or unmark if not.
Feedback to us

Develop and promote your apps in Windows Store
- Reply
Ict-Guy

Member

106 Points

19 Posts
Re: dropdown list default value

May 15, 2012 11:31 AM|LINK
try

@Html.DropDownListFor(model => model.ChildItems[i].RestrictionValue,
                                                               from Project.Core.Enums.Items.Restriction state in Enum.GetValues(typeof(Project.Core.Enums.Items.Restriction))
                                                               select new SelectListItem() { Text = state.ToString(), Value = ((int)state).ToString() }
                                                         ,"Select", null
                                        )

The syntax for DropDownListFor you used should be as below:
```
public static MvcHtmlString DropDownListFor<TModel, TProperty>(
	this HtmlHelper<TModel> htmlHelper,
	Expression<Func<TModel, TProperty>> expression,
	IEnumerable<SelectListItem> selectList,
	string optionLabel,
	Object htmlAttributes
)

or 
```
```
public static MvcHtmlString DropDownListFor<TModel, TProperty>(
	this HtmlHelper<TModel> htmlHelper,
	Expression<Func<TModel, TProperty>> expression,
	IEnumerable<SelectListItem> selectList,
	string optionLabel,
 IDictionary<string, Object> htmlAttributes
)
```
```
 
```
"Mark As Answer" if it helps".
- Edited by Ict-Guy on May 15, 2012 11:36 AM
- Marked as answer by Young Yang - MSFT on May 26, 2012 01:07 AM
- Reply
BlackShadows

Member

4 Points

28 Posts

Re: dropdown list default value

May 15, 2012 11:55 AM|LINK

try do it with Json and Ajax its simple way to do it.

http://www.ienablemuch.com/2011/05/cascading-dropdownlist-using-aspnet-mvc.html?showComment=1333529459280#c4027748902216758509
- Reply
Doctor Sid

Member

156 Points

46 Posts

Re: dropdown list default value

May 15, 2012 12:46 PM|LINK

where exactly does the exception occur?
i guess it occurs when accessing the Value property of a nullable that doesn't hold a value

if 'nullable' doesn't mean anything to you, plz google it
- Edited by Doctor Sid on May 15, 2012 12:47 PM