Consider the following model:
public class TagType
{
public int Id { get; set; }
public string Description { get; set; }
}
public class Tag
{
public int Id { get; set; }
public string Description { get; set; }
public TagType TagType { get; set; }
public DropDownListViewModel TagTypeViewModel { get; set; }
public int TagTypeId { get; set; }
}
I have the following Action in a controller:
public ActionResult Edit(int id)
{
// Load from database
IEnumerable<TagType> tagTypes = TagTypeDal.GetAll().ToList();
Tag tag = TagDal.Get(id);
tag.TagTypeViewModel = new DropDownListViewModel();
tag.TagTypeViewModel.Items = new List<SelectListItem>();
tag.TagTypeViewModel.Items.Add(new SelectListItem { Text = "None", Value = "-1" });
tag.TagTypeViewModel.Items.AddRange(tagTypes
.Select(tt => new SelectListItem
{
Text = tt.Description,
Value = tt.Id.ToString(),
Selected = tt.Id == tag.TagType.Id
}).ToList());
return View(tag);
}
The select list has one element that has Selected=true, and it's not the first element.
And on my Edit.cshtml I have:
#model Models.Tag
#Html.DropDownListFor(model => model.TagTypeId,
#Model.TagTypeViewModel.Items,
new { #class = "form-control" })
My problem is that the generated drop down never selects the element that has Selected=true, it always shows the first element.
Am I calling the wrong overload for DropDownListFor? Or am I building the select list wrong? Or is it somethig else?
You should fill model.TagTypeId with selected TagTypeId in your Controller.
DropDownListFor selected value depends on first parameter value.
Related
Ok, I'm trying to do a proper dropdown in Core 3.1. In this example https://learn.microsoft.com/en-us/aspnet/core/mvc/views/working-with-forms?view=aspnetcore-3.1#the-select-tag-helper
Model has a new list with hardcoded values
public string Country { get; set; }
public List<SelectListItem> Countries { get; } = new List<SelectListItem>
{
new SelectListItem { Value = "MX", Text = "Mexico" },
new SelectListItem { Value = "CA", Text = "Canada" },
new SelectListItem { Value = "US", Text = "USA" },
};
I looked for examples where the list is coming from the database but they are very inconsistent. The only way I was able to do the dropdown list is with the ViewBag which is not advised.
I have two models. 1.
public partial class Glossary
{
public int UniqueId { get; set; }
public int Category { get; set; }
public string DisplayText { get; set; }
}
which is my view model
public partial class AdminUser
{
[Key]
public int Id { get; set; }
public string UserName { get; set; }
public string UserLocation { get; set; }
public string UserStatus { get; set; }
//public IEnumerable<Glossary> Glossary { get; set; } //I used this for ViewBag
public List<SelectListItem> UserLocations { get; } = new List<SelectListItem>
{
according to the example my query should go here
};
}
Here is my controller:
public IActionResult Create()
{
// This is the ViewBag that worked with HTML helpers, but I'm trying to use tag-helpers.
/*IEnumerable<SelectListItem> LocationsList = _context.Glossary.Where(x => x.Category == 1).Select(x => new SelectListItem
{
Value = x.UniqueId.ToString(),
Text = x.DisplayText
});
ViewBag.LocationsList = LocationsList;
*/
return View();
}
All examples that found were hardcoded lists and nothing with getting it from the database. What is the proper way to get the data from the Glossary table through the view model with ViewBag? Any pointers are appreciated.
ALSO:
When using this example: Select Tag Helper in ASP.NET Core MVC
When I used
public SelectList Employees { set; get; }
I got error: InvalidOperationException: The entity type 'SelectListGroup' requires a primary key to be defined. If you intended to use a keyless entity type call 'HasNoKey()'.
Both of my tables have PK and adding [Key] to Glossary model didn't fix it.
If you'd like to retrieve data from db and populate a dropdown with retrieved data through a view model (or ViewBag), you can refer to following code snippet.
In AdminUser view model class, include these properties
public string Selected_Glossary { get; set; }
public List<SelectListItem> Glossary_List { get; set; }
In controller
public IActionResult Create(AdminUser model)
{
var adminuser_model = new AdminUser
{
UserName="test"
//for other properties
};
//retrieve data from Glossary table
var items = _context.Glossary.Where(x => x.Category == 1).Select(x => new SelectListItem
{
Value = x.UniqueId.ToString(),
Text = x.DisplayText
}).ToList();
//pass dropdown items through a view model
adminuser_model.Glossary_List = items;
////pass dropdown items through ViewBag
//ViewBag.Glossary_List = items;
return View(adminuser_model);
}
In view page
#model AdminUser
#{
ViewData["Title"] = "Create";
}
<h1>Create</h1>
<form asp-controller="Home" asp-action="Create" method="post">
<select asp-for="Selected_Glossary" asp-items="Model.Glossary_List"></select>
#*populate it through ViewBag*#
#*<select asp-for="Selected_Glossary" asp-items="ViewBag.Glossary_List"></select>*#
<input type="submit" value="Submit" />
</form>
Test Result
I have a model DropDownConfiguration which is fetching values from database and populating the dropdown list.
Model:
public class DropDownConfiguration
{
public int ID { get; set; }
public int Quarter { get; set; }
public int Year { get; set; }
public string Project { get; set; }
public string LineID { get; set; }
}
html:
#Html.DropDownList("Project", new SelectList(Model.dropConfig, "ID", "Project"), "-- Select Project --", new { required = true, #class = "form-control" })
I have another model DetailsConfiguration which has all the fields which need be saved into the database.
public class DetailsConfiguration
{
public int Quarter { get; set; }
public int Year { get; set; }
public string Project { get; set; }
public string ItemModel { get; set; }
}
Controller HttpPost:
[ActionName("DetailsForm")]
[HttpPost]
public ActionResult DetailsForm(DetailsViewModel model, FormCollection form)
{
DetailsConfiguration detailsConfig = new DetailsConfiguration();
detailsConfig.Quarter = Convert.ToInt32(form["Quarter"]);
detailsConfig.Year = Convert.ToInt32(form["Year"]);
detailsConfig.Project = model.detailsConfig.Project;
detailsConfig.ItemModel = model.detailsConfig.ItemModel;
detailsConfig.LineID = model.detailsConfig.LineID;
floorService.SaveDetails(detailsConfig);
ModelState.Clear();
ViewBag.message = "Success";
return View("DetailsForm");
}
Is there anyway to do something like:
model.detailsConfig.Project = model.dropConfig.Project
I need the selection of Project to be posted back to database through DetailsConfiguration.
You could create a mapper which sets the values of the properties in DropDownConfiguration to DetailsConfiguration.
When you change the dropdown you send the selected DropDownConfiguration to the server. You know exactly what properties you can expect here so you can do something like this:
[HttpPost]
public IHttpActionResult AddDetailsConfiguration(DropDownConfiguration parameter)
{
//check here if values in parameter are set
var detailsConfiguration = new DetailsConfiguration {
Quarter = parameter.Quarter,
Year = parameter.Year,
Project = parameter.Project
}
//Insert detailsConfiguration to database
Return Ok();
}
Note that you have to make sure you send a DropDownConfiguration object on selecting a dropdown item. You could also only send the values you need like this:
[HttpPost]
public IHttpActionResult AddDetailsConfiguration(int quarter, int year, string project)
{
//Check here if values in parameter are set and if values are correct
var detailsConfiguration = new DetailsConfiguration
{
Quarter = quarter,
Year = year,
Project = project
}
//Insert detailsConfiguration to database
Return Ok();
}
I need to create a view with a form where is a group of RadioButtons with TextBox for each of them. Then I want the Model to be filled with value in TextBox and value of selected RadioButton. I faced to the problem that I can't send value of coresponding to selected RadioButton TextBox.
It looks like this
There is my Model
public class CertainAnswersViewModel
{
public int SelectedValue { get; set; }
public string TextAnswer { get; set; }
public bool IsInput { get; set; }
public List<CertainAnswer> CertainAnswers { get; set; }
}
View
#using MY_BUKEP.Areas.Survey.Models;
#model CertainAnswersViewModel
#using (Html.BeginForm())
{
foreach (var answer in Model.CertainAnswers)
{
#Html.RadioButtonFor(m => m.SelectedValue, answer.IdOption, new { id = "" })
#Html.TextBoxFor(m => m.TextAnswer);
<br />
}
<input type="submit" />
}
And there are two methods in Controller
[HttpGet]
public ViewResult Test()
{
CertainAnswer ca1 = new CertainAnswer() { IdOption = 1 };
CertainAnswer ca2 = new CertainAnswer() { IdOption = 2 };
CertainAnswersViewModel cavm = new CertainAnswersViewModel();
cavm.CertainAnswers = new List<CertainAnswer>();
cavm.CertainAnswers.Add(ca1);
cavm.CertainAnswers.Add(ca2);
return View("TestView", cavm);
}
[HttpPost]
public void Test(CertainAnswersViewModel cavm)
{
Answer a = new Answer();
a.val = cavm.TextAnswer;
a.idOption = cavm.SelectedValue;
}
Below is supposed result that I would like to achive
Would appreciate any help!
You current implementation is creating duplicate textboxes for the same property and when you submit the form only the value of the first textbox will be bound (if the user was to select the 3rd option and fill in the associated textbox, the value of TextAnswer will be null because the textbox associated with the 2nd option is empty. In addition your model(s) cannot generate the view you have shown in the second image because each CertainAnswer property also requires a value to indicate if an associated textbox is required (I'm assuming for some options, it may not be).
Your models would need to be (not I have change some class and property names to better describe what they represent)
public class PossibleAnswerVM
{
public int ID { get; set; }
public string Description { get; set; }
public bool RequireAdditionalText { get; set; }
}
public class QuestionVM
{
public int ID { get; set; }
public string Description { get; set; }
[Required(ErrorMesage = "Please select an option")]
public int SelectedAnswer { get; set; }
public string AdditionalText { get; set; }
public IEnumerable<PossibleAnswer> PossibleAnswers { get; set; }
}
and the code in your controller
QuestionVM model = new QuestionVM()
{
ID = 1,
Description = "If you could return to the past, what would you choose?",
PossibleAnswers = new List<PossibleAnswer>()
{
new PossibleAnswer(){ ID = 1, Description = "Apply to another university" },
new PossibleAnswer(){ ID = 2, Description = "Apply to the same ...", RequireAdditionalText = true }
}
};
return View(model);
and the view
#model QuestionVM
#using (Html.BeginForm())
{
#Html.HiddenFor(m => m.Question.ID)
#Html.DisplayFor(m => m.Question.Description)
foreach(var option in Model.PossibleAnswers)
{
<label>
#Html.RadioButtonFor(m => m.SelectedAnswer, option.ID, new { id = "" data_textrequired = option.RequireAdditionalText })
<span>#option.Description</span>
</label>
}
#Html.ValidationMessageFor(m => m.SelectedAnswer)
#Html.TextBoxFor(m => m.AdditionalText)
<input type="submit" value="Save" />
}
Note that a data-textrequired has been added so that you could use javascript to show/hide the textbox based on the selected option. You could also use javascript to position the textbox adjacent the selected option if necessary
I wanna implement MVC paging so on the Index Action its working.
public ActionResult Index(int? page)
{
using (NorthwindEntities db = new NorthwindEntities())
{
CustomersViewModel model = new CustomersViewModel();
//model.Customers = db.Customers.OrderBy(m => m.CustomerID).OrderByDescending(m=>m.CustomerID).Take(10).ToList();
model.Customers = db.Customers.OrderBy(m => m.CustomerID).OrderByDescending(m=>m.CustomerID).Take(10).ToList().ToPagedList(page ?? 1,5);
model.SelectedCustomer = null;
var list = new List<int>();
for (int i = 1; i <= 20; i++)
{
list.Add(i);
}
SelectList selectedList = new SelectList(list);
ViewBag.DdList = selectedList;
//model.Countries = db.Countries.ToList();
model.CountryList = new SelectList(BLDDLCountry.GetCountry(), "CountryId", "CountryName");
model.DisplayMode = "WriteOnly";
return View(model);
}
}
Now on the View
#Html.PagedListPager(Model, page => Url.Action("Index", new {page, pagesize = 5 }))
Is accepted only if i decorate my View Model with IPagedList
#model PagedList.IPagedList<SingleCRUD.Models.CustomersViewModel>
Now as I am using
public IEnumerable<Customer> Customers { get; set; }
On My ViewModdel
The View is not accepting the Customers
#{
foreach (var item in Model.Customers)
{
if (Model.SelectedCustomer != null)
{
if (item.CustomerID ==
Model.SelectedCustomer.CustomerID)
{
#:<tr class="SelectedCustomer">
}
else
{
#:<tr>
}
}
else
{
#:<tr>
}
<td>#item.CustomerID</td>
<td>#item.CompanyName</td>
#*<td><input type="submit"
formaction="/home/select/#item.CustomerID"
value="Select" /></td>*#
<td><input type="submit"
formaction="/home/Edit/#item.CustomerID"
value="Edit" /></td>
<td></td>
#:</tr>
}
}
And Go to definition has stopped on Customers after changing the name space.
My View Model
public class CustomersViewModel
{
public int CustomerID { get; set; }
public string CompanyName { get; set; }
public string ContactName { get; set; }
public string ContactTitle { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string Region { get; set; }
public Nullable<int> PostalCode { get; set; }
public string Country { get; set; }
public Nullable<int> Phone { get; set; }
public Nullable<int> Fax { get; set; }
public IEnumerable<Customer> Customers { get; set; }
public Customer SelectedCustomer { get; set; }
public string DisplayMode { get; set; }
public List<Country> Countries { get; set; }
public SelectList CountryList { get; set; }
}
So I am facing issue at the view level how do I correctly fix it.
Tried these changes
Model
public PagedList<Customer> Customers { get; set; }
View
#model SingleCRUD.Models.CustomersViewModel
#using PagedList;
#using PagedList.Mvc;
#Html.PagedListPager(Model.Customers, page => Url.Action("Index", new { page, pagesize = 5 }))
Action
model.Customers = (PagedList<Customer>)db.Customers.OrderBy(m => m.CustomerID).ToPagedList(page ?? 1, 5);
Had to explicitly convert it to Paged List as there was a conversion error not sure whether its correct.
Run Time error on View.
'System.Web.Mvc.HtmlHelper' does not contain a definition for 'PagedListPager' and the best extension method overload 'PagedList.Mvc.HtmlHelper.PagedListPager(System.Web.Mvc.HtmlHelper, PagedList.IPagedList, System.Func)' has some invalid arguments
Error
Error 1 Cannot implicitly convert type 'PagedList.IPagedList' to 'PagedList.PagedList'. An explicit conversion exists (are you missing a cast?)
Using
#Html.PagedListPager(Model.Customers, page => Url.Action("Index", new { page, pagesize = 5 }))
on View tried writing this in the form tag as well as out side the form tag.
Its a bit unclear what you claiming. #model PagedList.IPagedList<CustomersViewModel> will not work since your model is CustomersViewModel but it will work if your use #model CustomersViewModel.
If you wanting to display a paged list of Customer, then your model property needs to be
public IPagedList<Customer> Customers { get; set; }
and in the view use
#Html.PagedListPager(Model.Customers, page => Url.Action("Index", new {page, pagesize = 5 }))
i have a model and i send substring one field on this model and return to a view for show in gridview
my model is:
public class News
{
public int ID { get; set; }
[MaxLength(300)]
public string Title { get; set; }
[DataType(DataType.MultilineText)]
[MaxLength]
public string Content { get; set; }
[ReadOnly(true)]
public DateTime Date { get; set; }
[Column("PictureID")]
public virtual Picture Picture { get; set; }
//public IList<Picture> PicID { get; set; }
[Column("NewsTypeID",Order=1)]
public virtual NewsType NewsType { get; set; }
public ICollection<Tag> Tags { get; set; }
public News()
{
Tags = new List<Tag>();
}
}
when i send this model by myController:
public ActionResult ShowNews()
{
var data = new DatabaseContext();
var news = data.newsInfo.ToList();
return View(news);
}
it is ok and show properly in gridview
but if send this model by this cod in controller:
public ActionResult ShowNews()
{
var data = new DatabaseContext();
var news = data.newsInfo.Select(x => new { Content = x.Content.Substring(0,200), x }).ToList();
return View(news);
}
show this Error:
The model item passed into the dictionary is of type 'System.Collections.Generic.List1[<>f__AnonymousType02[System.String,NewsAgency.Models.News]]', but this dictionary requires a model item of type 'System.Collections.Generic.List`1[NewsAgency.Models.News]'.
i have send substring one of the field
what is problem?
You have created list of anonymous objects in this statement:
data.newsInfo.Select(x => new { Content = x.Content.Substring(0,200), x }).ToList();
And you have send it as model to your view:
View(news);
But, in your view you have set model type as List<News>. So, the exception is throwned. Try to change your code as:
var news = data.newsInfo.AsEnumerable().Select(x => { x.Content = x.Content.Substring(0,200); return x; }).ToList();
If you want to send whole Content values along with substrings, then I recommend to use first way and get the substring of all item's Content with razor inside view.