cant render view via renderAction - asp.net-mvc-3

Hi im using RenderAction helper and during rendering i have this error:
Error executing child request for
handler
'System.Web.Mvc.HttpHandlerUtil+ServerExecuteHttpHandlerAsyncWrapper'.
Controller code:
public ActionResult GetSearcher()
{
SearcherLines sl = new SearcherLines()
{
RegionList = db.Region.ToList(),
CategoryList = db.Category.ToList(),
SearchValue = null
};
return PartialView(sl);
}
ViewModel
public class SearcherLines
{
public List<Region> RegionList { get; set; }
public List<Category> CategoryList { get; set; }
public string SearchValue { get; set; }
}
partialView
#model IEnumerable<MasterProject.JobForYou.v3.Models.ViewModels.SearcherLines>
#foreach (var i in Model)
{
<p>#i.CategoryList</p><br />
}
Please help.

Try setting OutputCache attribute on controller action

Related

more models on a mvc3 page

Could I have more models on a razor page?
for example when I have more grid controls each with an area(a template) for editing the data,and after that i want to save the data and see it in the grid.
You can do something like the example below (this is a very over simplified example):
public class AnimalDataViewModel
{
public List<Dog> DogData { get; set; }
public List<Cat> CatData { get; set; }
public List<Mouse> MouseData { get; set; }
public AnimalDataViewModel()
{
this.DogData = new List<Dog>();
this.CatData = new List<Cat>();
this.MouseData = new List<Mouse>();
}
}
Then in your action method:
public ActionResult DisplayAnimalDataGrids()
{
AnimalDataViewModel model = new AnimalDataViewModel();
model.DogData = this.myDataService.GetDogData();
model.CatData = this.myDataService.GetCatData();
model.MouseData = this.myDataService.GetMouseData();
return View(model);
}
Then in your view:
#model AnimalDataViewModel
#Html.Grid(Model.DogData)
#Html.Grid(Model.CatData)
#Html.Grid(Model.MouseData)

how to bind a dropdownlist to model properly to be able to pass values back from view to controller

I am trying to update a compound page model which as one of its properties has a list of objects.
My Model looks like this:
public class PageViewModel
{
public ProgramListVM ProgramsDDL { get; set; }
public PageViewModel()
{
this.ProgramsDDL = new ProgramListVM();
}
}
The ProgramListVM class is:
public class ProgramListVM
{
public List<ProgramVM> Program_List { get; set; }
public int SelectedValue { get; set; }
public ProgramListVM()
{
this.Program_List = new List<ProgramVM>();
this.SelectedValue = 0;
}
}
and ProgramVM is:
public class ProgramVM
{
public int ProgramID { get; set; }
public string ProgramDesc { get; set; }
public ProgramVM(int id, string code)
{
this.ProgramID = id;
this.ProgramDesc = code;
}
}
I try to render this dropdownlist by the following two:
1-
<%: Html.DropDownList("ProgramsDDL", new SelectList(Model.Page6VM.ProgramsDDL.Program_List, "ProgramID", "ProgramDesc", Model.Page6VM.ProgramsDDL.SelectedValue))%>
2-
<%: Html.DropDownListFor(m => m.Page6VM.ProgramsDDL.Program_List, new SelectList(Model.Page6VM.ProgramsDDL.Program_List, "ProgramID", "ProgramDesc"), Model.Page6VM.ProgramsDDL.SelectedValue)%>
But when I try to update my model through a controller action
[HttpPost]
public ActionResult UpdateUser(PageViewModel model)
{
}
model.ProgramsDDL.count is zero.
What is the best way to render this dropdownlist and be able to set the selected index, and also be able to send the selected index back to the controller?
You mixed up the parameters for Html.DropDownListFor(). Code sample below should work.
<%: Html.DropDownListFor(m => m.SelectedValue,
new SelectList(Model.Page6VM.ProgramsDDL.Program_List, "ProgramID", "ProgramDesc"),
null) %>
You also should have a SelectedValue in your model that's posted back.
public class PageViewModel
{
public ProgramListVM ProgramsDDL { get; set; }
public int SelectedValue { get; set; }
public PageViewModel()
{
this.ProgramsDDL = new ProgramListVM();
}
}
Also default model binder can't map complex collections to your model. You probably don't need them in your post action anyway.

html.dropdownlistfor() troubles...getting null reference exceptions

I've tried to follow a few examples from here and a couple other resources to just create a very simple member in my viewmodel and display it as a dropdown list on my view with a dropdownlistfor() helper. I can't seem to wrap my head around it and it's not working with what I'm trying.
here's my viewmodel:
public class Car
{
public int CarId { get; set; }
public string Name { get; set; }
}
public class MyViewModel
{
public IEnumerable<Car> Cars = new List<Car> {
new Car {
CarId = 1,
Name = "Volvo"
},
new Car {
CarId = 2,
Name = "Subaru"
}
};
public int MyCarId { get; set; }
}
and here is my view:
#Html.DropDownListFor(m => m.MyCarId, new SelectList(Model.Cars, "CarId", "Name"))
and here is my controller:
public ActionResult MyView()
{
return View();
}
You need to make sure you send the Model to your View:
public ActionResult Index()
{
var myViewModel = new MyViewModel()
return View(myViewModel);
}
And in your View you need to make sure you're defining your Model:
#model namespace.MyViewModel
You example works fine, I think you forgot to send MyViewModel in POST Action.
[HttpPost]
public ActionResult Index(MyViewModel model)
{
return View(model);
}

How can I get the values from a ListBox in my ASP.NET MVC 3 controller?

Here is my Item class:
public class Item
{
public int ItemId { get; set; }
public string Name { get; set; }
public virtual List<Tag> Tags { get; set; }
}
Here's my GET action:
//
// GET: /Home/AddItem/
public ActionResult AddItem()
{
List<Tag> Tags = Db.Tags.ToList();
ViewBag.Tags = new SelectList(Tags, "TagId", "Name");
return View();
}
Here's my view:
#model MySite.Models.Item
#using (Html.BeginForm()) {
//...
#Html.ListBox("Tags")
//...
}
Finally, here's my POST action:
//
// POST: /Home/AddItem/
[HttpPost]
public ActionResult AddItem(Item Item)
{
//...
List<Tag> NewItemTags = Item.Tags.ToList();
//...
}
The problem is that Item.Tags.ToList() is always empty in the POST action... like the selected values of the ListBox aren't being sent at all.
Stuck here. Please help.
I am assuming that TagId is integer.
public class Item
{
public int ItemId { get; set; }
public string Name { get; set; }
public virtual List<int> Tags { get; set; }
}
[HttpPost]
public ActionResult AddItem(Item Item)
{
List<int> NewItemTags = Item.Tags.ToList();
}
Also in View your ListBox should have Name = "Tags". If you are using ListBoxFor then no need to worry.
If still issue provide further information related to view.

Creating Dropdown List in MVC3

I am trying to create a dropdown list to display all the value in a custom collection class
such as
public class MyCustomClassCollection
{
public List<MyCustomClass> {get;set;}
}
I want it to show the Description:string of each MyCustomClass
I tried
<%: Html.DropDownList "Description", MyCustomClass %>
Resharper suggests that I cast MyCustomClass to IEnemerable
but the server returns an unable to cast error.
Any Idea how I can create this DropDownList?
__Modification___
public class ViewModel
{
public Detail detail { get; set; }
}
public class Detail //Inherited from webservce
{
public CustomClassCollection {get;set;}
.... Other Properties, a.k.a Custom Classes
}
public class CustomClassCollection
{
public List<CustomClass> {get;set;}
}
public class CustomClass {
public int Id {get;set;}
public string Description{get;set;}
... other properties
}
public ActionResult Index(int? id, DateTime? date)
{
if (id.Equals(null))
id = ######### ;
if (date.Equals(null))
date = DateTime.Today;
var vm = new ViewModel
{
Detail = _repository.Detail((int)id,(DateTime)date)
};
return View(vm);
}
The second argument of the DropDownList helper must be an IEnumerable<SelectListItem> or a SelectList which implements this interface for that matter. So in your controller action organize in such a way that you convert your custom collection into an IEnumerable<SelectListItem>. As always you could start by writing a view model:
public class MyViewModel
{
public string SelectedDescription { get; set; }
public SelectList Descriptions { get; set; }
}
and then have your controller action query the custom list and populate the view model which will be passed to the view:
public ActionResult Index()
{
var descriptions = yourCustomCollection.MyCustomClass.Select(x => new
{
Value = x.Description,
Text = x.Description
});
var model = new MyViewModel
{
Descriptions = new SelectList(descriptions, "Value", "Text")
};
return View(model);
}
and finally in your strongly typed view:
<%= Html.DropDownListFor(x => x.SelectedDescription, Model.Decriptions) %>
UPDATE:
After posting your updated models (which by the way are still incomplete and impossible to compile as you haven't provided any property names), here's an example:
public class ViewModel
{
public int SelectedId { get; set; }
public Detail Detail { get; set; }
}
public class Detail
{
public CustomClassCollection MyCollection { get; set; }
}
public class CustomClassCollection
{
public List<CustomClass> CustomClass { get; set; }
}
public class CustomClass
{
public int Id { get; set; }
public string Description { get; set; }
}
public class HomeController : Controller
{
public ActionResult Index()
{
var vm = new ViewModel
{
Detail = new Detail
{
MyCollection = new CustomClassCollection
{
CustomClass = new List<CustomClass>
{
new CustomClass
{
Id = 1,
Description = "description 1",
},
new CustomClass
{
Id = 2,
Description = "description 2",
},
new CustomClass
{
Id = 3,
Description = "description 3",
},
}
}
}
};
return View(vm);
}
}
and in the view:
<%= Html.DropDownListFor(
x => x.SelectedId,
new SelectList(Model.Detail.MyCollection.CustomClass, "Id", "Description")
) %>
What you have to understand in order to define a dropdown list in ASP.NET MVC ius that you need 2 things:
A scalar property to bind the selected value to (SelectedId in my example)
A collection to bind the list to (Model.Detail.MyCollection.CustomClass in the example)

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