I have a MVC3 page that has to dropdownList contains Sex(male,female) and Role(admin,Operator), in RegisterViewModel I have done like this :
public List<SelectListItem> SelectedItemForSex { get; set; }
public List<SelectListItem> SelectedItemForRole { get; set; }
public string SearchText { get; set; }
public string SelectedValue { get; set; }
//public string SelectedValueForRole { get; set; }
public static RegisterViewModel Get()
{
var model = new RegisterViewModel { SelectedItemForSex = new List<SelectListItem>() };
model.SelectedItemForSex.Add(new SelectListItem() { Text = "Male", Value = "1" });
model.SelectedItemForSex.Add(new SelectListItem() { Text = "Femle", Value = "2" });
model.SelectedItemForRole.Add(new SelectListItem() {Text = "Administrator", Value = "1"});
model.SelectedItemForRole.Add(new SelectListItem() {Text = "Operator", Value = "2"});
return model;
}
and in get action of Register I have this code :
public ActionResult Create()
{
var model = RegisterViewModel.Get();
return View(model);
}
and also in razor :
<div>
#Html.LabelFor(register => register.Sex)
#Html.DropDownListFor(register => register.SelectedValue, new SelectList(Model.SelectedItemForSex, "Value", "Text"))
</div>
<div>
#Html.LabelFor(register => register.Role)
#Html.DropDownListFor(register => register.SelectedValue, new SelectList(Model.SelectedItemForRole, "Value", "Text"))
</div>
<div>
I know I have Not initialize selectedListItem for Administrator and operator , I wanna to send all of this 4 value via Get() method, How can I do this ??
Related
I'm new towards MVC3 Razor. Currently, I'm facing this error "Object reference not set to an instance of an object.", which I have no idea what is this about.
In Model
public List<SelectListItem> CatList { get; set; }
[Display(Name = "Category")]
public string CatID { get; set; }
In Controller
public ActionResult DisplayCategory()
{
var model = new CatModel();
model.CatList = GetCat();
return View(model);
}
private List<SelectListItem> GetCat()
{
List<SelectListItem> itemList = new List<SelectListItem>();
itemList.Add(new SelectListItem { Text = "1", Value = "1" });
itemList.Add(new SelectListItem { Text = "2", Value = "2" });
return itemList;
}
In CSHTML
#using (Html.BeginForm())
{
<table>
<tr>
<td>#Html.LabelFor(c => c.CatID)</td>
<td>#Html.DropDownListFor(c => c.CatID, Model.CatList)</td>
</tr>
</table>
}
Thanks for any help.
I suspect that you have a POST action in which you forgot to reassign the CatList property of your view model so you are getting the NRE when you submit the form, not when the form is initially rendered:
public ActionResult DisplayCategory()
{
var model = new CatModel();
model.CatList = GetCat();
return View(model);
}
[HttpPost]
public ActionResult Index(CatModel model)
{
// some processing ...
// since we return the same view we need to populate the CatList property
// the same way we did in the GET action
model.CatList = GetCat();
return View(model);
}
private List<SelectListItem> GetCat()
{
List<SelectListItem> itemList = new List<SelectListItem>();
itemList.Add(new SelectListItem { Text = "1", Value = "1" });
itemList.Add(new SelectListItem { Text = "2", Value = "2" });
return itemList;
}
I am new to MVC3
I am finding it difficult to create an dropdown.I have gone through all the other related questions but they all seem to be complex
I jus need to create a dropdown and insert the selected value in database
Here is what i have tried:
//Model class:
public int Id { get; set; }
public SelectList hobbiename { get; set; }
public string filelocation { get; set; }
public string hobbydetail { get; set; }
//Inside Controller
public ActionResult Create()
{
var values = new[]
{
new { Value = "1", Text = "Dancing" },
new { Value = "2", Text = "Painting" },
new { Value = "3", Text = "Singing" },
};
var model = new Hobbies
{
hobbiename = new SelectList(values, "Value", "Text")
};
return View();
}
//Inside view
<div class="editor-label">
#Html.LabelFor(model => model.hobbiename)
</div>
<div class="editor-field">
#Html.DropDownListFor( x => x.hobbiename, Model.hobbiename )
#Html.ValidationMessageFor(model => model.hobbiename)
</div>
I get an error:System.MissingMethodException: No parameterless constructor defined for this object
You are not passing any model to the view in your action. Also you should not use the same property as first and second argument of the DropDownListFor helper. The first argument that you pass as lambda expression corresponds to a scalar property on your view model that will hold the selected value and which will allow you to retrieve this value back when the form is submitted. The second argument is the collection.
So you could adapt a little bit your code:
Model:
public class Hobbies
{
[Required]
public string SelectedHobbyId { get; set; }
public IEnumerable<SelectListItem> AvailableHobbies { get; set; }
... some other properties that are irrelevant to the question
}
Controller:
public class HomeController: Controller
{
public ActionResult Create()
{
// obviously those values might come from a database or something
var values = new[]
{
new { Value = "1", Text = "Dancing" },
new { Value = "2", Text = "Painting" },
new { Value = "3", Text = "Singing" },
};
var model = new Hobbies
{
AvailableHobbies = values.Select(x => new SelectListItem
{
Value = x.Value,
Text = x.Text
});
};
return View(model);
}
[HttpPost]
public ActionResult Create(Hobbies hobbies)
{
// hobbies.SelectedHobbyId will contain the id of the element
// that was selected in the dropdown
...
}
}
View:
#model Hobbies
#using (Html.BeginForm())
{
#Html.LabelFor(x => x.SelectedHobbyId)
#Html.DropDownListFor(x => x.SelectedHobbyId, Model.AvailableHobbies)
#Html.ValidationMessageFor(x => x.SelectedHobbyId)
<button type="submit">Create</button>
}
I would create them as
Model:
public class ViewModel
{
public int Id { get; set; }
public string HobbyName { get; set; }
public IEnumerable<SelectListItem> Hobbies {get;set; }
public string FileLocation { get; set; }
public string HobbyDetail { get; set; }
}
Action
public ActionResult Create()
{
var someDbObjects= new[]
{
new { Id = "1", Text = "Dancing" },
new { Id = "2", Text = "Painting" },
new { Id = "3", Text = "Singing" },
};
var model = new ViewModel
{
Hobbies = someDbObjects.Select(k => new SelectListItem{ Text = k, Value = k.Id })
};
return View(model);
}
View
<div class="editor-label">
#Html.LabelFor(model => model.HobbyName)
</div>
<div class="editor-field">
#Html.DropDownListFor(x => x.HobbyName, Model.Hobbies )
#Html.ValidationMessageFor(model => model.HobbyName)
</div>
I looked at similar posts but nothing working for my case.
I have a form which loads fine and I see the categories dropdown with all categories in it.
The problem is when I try to post the form.
I get this error:
The ViewData item that has the key 'Category' is of type 'System.String' but must be of type 'IEnumerable'.
#Html.DropDownList("Category", Model.Categories) <-- red color
Here is my view:
#using (Html.BeginForm("Save", "Album", FormMethod.Post, new { id = "frmNewAlbum" }))
{
#Html.DropDownList("Category", Model.Categories)
}
Here is my model:
public class AlbumModel
{
public string Title { get; set; }
public string Category { get; set; }
public List<SelectListItem> Categories { get; set; } <-- holds categories
}
This is the controller actions to view the page:
[HttpGet]
public ActionResult Save()
{
var model = new AlbumModel();
var categories = new List<SelectListItem>() { new SelectListItem() { Text = "-- pick --" } };
categories.AddRange(svc.GetAll().Select(x => new SelectListItem() { Text = x.Name, Value = x.Name }));
model.Categories = categories;
return View(model);
}
Action that receives the post:
[HttpPost]
public ActionResult Save(AlbumModel model)
{
var album = new AlbumDoc()
{
Category = model.Category,
Title = model.Title,
};
svc.SaveAlbum(album);
return View(model);
}
In your POST action you seem to be redisplaying the same view but you are not populating the Categories property on your view model which will contain the dropdown list values. And by the way I would recommend you using strongly typed helper. So:
public class AlbumController: Controller
{
[HttpGet]
public ActionResult Save()
{
var model = new AlbumModel();
model.Categories = GetCategories();
return View(model);
}
[HttpPost]
public ActionResult Save(AlbumModel model)
{
var album = new AlbumDoc()
{
Category = model.Category,
Title = model.Title,
};
svc.SaveAlbum(album);
model.Categories = GetCategories();
return View(model);
}
private IList<SelectListItem> GetCategories()
{
return svc
.GetAll()
.ToList()
.Select(x => new SelectListItem
{
Text = x.Name,
Value = x.Name
});
}
}
and in your view:
#model AlbumModel
...
#using (Html.BeginForm("Save", "Album", FormMethod.Post, new { id = "frmNewAlbum" }))
{
#Html.DropDownListFor(
x => x.Category,
Model.Categories,
-- pick --
)
}
I want to have a dropdownlist in my view that displays a patient's ID, First Name, and Last Name. With the code below, it displays each patient's First Name. How can I pass all three properties into the viewbag and have them display in the dropdownlist?
Controller
public ActionResult Create()
{ViewBag.Patient_ID = new SelectList(db.Patients, "Patient_ID", "First_Name");
return View();
}
View
<div class="editor-field">
#Html.DropDownList("Patient_ID", String.Empty)
#Html.ValidationMessageFor(model => model.Patient_ID)
</div>
Thanks.
Ok, I have edited my code as follows, and I receive the error "There is no ViewData item of type 'IEnumerable' that has the key 'SelectedPatientId'."
Controller
public ActionResult Create()
{
var model = new MyViewModel();
{
var Patients = db.Patients.ToList().Select(p => new SelectListItem
{
Value = p.Patient_ID.ToString(),
Text = string.Format("{0}-{1}-{2}", p.Patient_ID, p.First_Name, p.Last_Name)
});
var Prescribers = db.Prescribers.ToList().Select(p => new SelectListItem
{
Value = p.DEA_Number.ToString(),
Text = string.Format("{0}-{1}-{2}", p.DEA_Number, p.First_Name, p.Last_Name)
});
var Drugs = db.Drugs.ToList().Select(p => new SelectListItem
{
Value = p.NDC.ToString(),
Text = string.Format("{0}-{1}-{2}", p.NDC, p.Name, p.Price)
});
};
return View(model);
}
View Model
public class MyViewModel
{
[Required]
public int? SelectedPatientId { get; set; }
public IEnumerable<SelectListItem> Patients { get; set; }
[Required]
public int? SelectedPrescriber { get; set; }
public IEnumerable<SelectListItem> Prescribers { get; set; }
[Required]
public int? SelectedDrug { get; set; }
public IEnumerable<SelectListItem> Drugs { get; set; }
}
View
#using (Html.BeginForm()) {
#Html.ValidationSummary(true)
#Html.DropDownListFor(
x => x.SelectedPatientId,
Model.Patients,
"-- Select patient ---"
)
#Html.ValidationMessageFor(x => x.SelectedPatientId)
<button type="submit">OK</button>
#Html.DropDownListFor(
x => x.SelectedPrescriber,
Model.Patients,
"-- Select prescriber ---"
)
#Html.ValidationMessageFor(x => x.SelectedPrescriber)
<button type="submit">OK</button>
}
I would recommend you not to use any ViewBag at all and define a view model:
public class MyViewModel
{
[Required]
public int? SelectedPatientId { get; set; }
public IEnumerable<SelectListItem> Patients { get; set; }
}
and then have your controller action fill and pass this view model to the view:
public ActionResult Create()
{
var model = new MyViewModel
{
Patients = db.Patients.ToList().Select(p => new SelectListItem
{
Value = p.Patient_ID.ToString(),
Text = string.Format("{0}-{1}-{2}", p.Patient_ID, p.First_Name, p.Last_Name)
});
};
return View(model);
}
and finally in your strongly typed view display the dropdown list:
#model MyViewModel
#using (Html.BeginForm())
{
#Html.DropDownListFor(
x => x.SelectedPatientId,
Model.Patients,
"-- Select patient ---"
)
#Html.ValidationMessageFor(x => x.SelectedPatientId)
<button type="submit">OK</button>
}
Easy way to accomplish that is just creating additional property on your model either by modifying model class or adding/modifying a partial class
[NotMapped]
public string DisplayFormat
{
get
{
return string.Format("{0}-{1}-{2}", Patient_ID, First_Name, Last_Name);
}
}
In my viewModel I have
public string Addressline1 { get; set; }
public List<SelectListItem> StateList
{
get
{
return State.GetAllStates().Select(state => new SelectListItem { Selected = false, Text = state.Value, Value = state.Value }).ToList();
}
}
In the view I have
#Html.DropDownListFor(model => model.StateCode, Model.StateList, "select")
when AddressLine1 is entered, then the statelist DropDownList selection is Required.How do I validate and show an error message when no state is selected in the Drop down list other than default "select" value?
Decorate your StateCode property with the [Required] attribute:
[Required(ErrorMessage = "Please select a state")]
public string StateCode { get; set; }
public IEnumerable<SelectListItem> StateList
{
get
{
return State
.GetAllStates()
.Select(state => new SelectListItem
{
Text = state.Value,
Value = state.Value
})
.ToList();
}
}
and then you could add a corresponding validation error message:
#Html.DropDownListFor(model => model.StateCode, Model.StateList, "select")
#Html.ValidationMessageFor(model => model.StateCode)
UPDATE:
Alright it seems that you want to conditionally validate this StateCode property depending on some other property on your view model. Now that's an entirely different story and you should have explained this in your original question. Anyway, one possibility is to write a custom validation attribute:
public class RequiredIfPropertyNotEmptyAttribute : ValidationAttribute
{
public string OtherProperty { get; private set; }
public RequiredIfPropertyNotEmptyAttribute(string otherProperty)
{
if (otherProperty == null)
{
throw new ArgumentNullException("otherProperty");
}
OtherProperty = otherProperty;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var property = validationContext.ObjectType.GetProperty(OtherProperty);
if (property == null)
{
return new ValidationResult(string.Format(CultureInfo.CurrentCulture, "{0} is an unknown property", new object[]
{
OtherProperty
}));
}
var otherPropertyValue = property.GetValue(validationContext.ObjectInstance, null) as string;
if (string.IsNullOrEmpty(otherPropertyValue))
{
return null;
}
if (string.IsNullOrEmpty(value as string))
{
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
return null;
}
}
and now decorate your StateCode property with this attribute, like so:
public string AddressLine1 { get; set; }
[RequiredIfPropertyNotEmpty("AddressLine1", ErrorMessage = "Please select a state")]
public string StateCode { get; set; }
Now assuming you have the following form:
#using (Html.BeginForm())
{
<div>
#Html.LabelFor(x => x.AddressLine1)
#Html.EditorFor(x => x.AddressLine1)
</div>
<div>
#Html.LabelFor(x => x.StateCode)
#Html.DropDownListFor(x => x.StateCode, Model.States, "-- state --")
#Html.ValidationMessageFor(x => x.StateCode)
</div>
<input type="submit" value="OK" />
}
the StateCode dropdown will be required only if the user entered a value into the AddressLine1 field.