Populating DropDownList in MVC 5
Here is my code for my AddNewProductViewModel
using AccessorizeForLess.Data;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Web;
namespace AccessorizeForLess.ViewModels
{
public class AddNewProductViewModel
{
public string Name { get; set; }
[DataType(DataType.MultilineText)]
public string Description { get; set; }
public decimal Price { get; set; }
public string AltText { get; set; }
public int Quantity { get; set; }
public string ImagePath { get; set; }
public HttpPostedFileBase Image { get; set; }
public List<ProductCategory> Category { get; set; }
}
}
Here's my Create method in my controller
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create(AddNewProductViewModel model)
{
ProductImageViewModel image = new ProductImageViewModel() { ImagePath = "/Content/ProductImages/" + model.Image.FileName, AltText = model.AltText };
ProductImage newImage = new ProductImage() { ImagePath = image.ImagePath, AltText = image.AltText };
entities.ProductImages.Add(newImage);
await entities.SaveChangesAsync();
int ImageId = newImage.ProductImageId;
Product product = new Product()
{
ProductImageId = ImageId,
ProductName = model.Name,
ProductDescription = model.Description,
ProductPrice = model.Price,
Quantity = model.Quantity
CategoryID = model.
};
string file = model.Image.FileName;
string path = Server.MapPath(@"~/Content/ProductImages");
string fullPath = path + @"\" + file;
try
{
model.Image.SaveAs(path + @"\" + file);
if (ModelState.IsValid)
{
entities.Products.Add(product);
await entities.SaveChangesAsync();
return RedirectToAction("Create");
}
}
catch (Exception ex)
{
ViewBag.Message = ex.ToString();
}
//ViewBag.ProductImageId = new SelectList(entities.ProductImages, "ProductImageId", "ImagePath", product.ProductImageId);
return View("Create");
}
And now when I try to populate my DropDownList in my opinion:
<div class="form-group">
@Html.LabelFor(model => model.Category, new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownListFor(model => model.Category.Id, new SelectList(Model.Category,"Value","Text"), "- Please Select -")
@Html.ValidationMessageFor(model => model.Category)
</div>
</div>
And this is the error I am getting:
CS0411: Type arguments for method 'System.Web.Mvc.Html.SelectExtensions.DropDownListFor (System.Web.Mvc.HtmlHelper, System.Linq.Expressions.Expression> System.Collections.Generic.IEnumerable, object)' could not be inferred from usage Try to specify the type of arguments explicitly.
EDIT
Here is the new AddNewProductViewModel
using AccessorizeForLess.Data;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Web;
namespace AccessorizeForLess.ViewModels
{
public class AddNewProductViewModel
{
public string Name { get; set; }
[DataType(DataType.MultilineText)]
public string Description { get; set; }
public decimal Price { get; set; }
public string AltText { get; set; }
public int Quantity { get; set; }
public string ImagePath { get; set; }
public HttpPostedFileBase Image { get; set; }
public ProductCategory Category { get; set; }
public int SelectedCategoryId { get; set; }
public List<ProductCategory> Categories { get; set; }
}
}
And my updated try at the dropdown
<div class="form-group">
@Html.LabelFor(model => model.Category, new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownListFor(model => model.SelectedCategoryId,
new SelectList(Model.Categories, "CategoryId", "CategoryName"), "- Please Select -")
@Html.ValidationMessageFor(model => model.Category)
</div>
</div>
Now I am getting NullReferenceException on this line
@Html.DropDownListFor(model => model.SelectedCategoryId,
Given my code, can someone please show me what I am doing wrong here, I have been struggling with this since last night.
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I solved the problem (thanks everyone for the advice). This is for those who might have problems like me.
I changed my Create method to look like this:
// GET: /Products/Create
public ActionResult Create()
{
var p = new AddNewProductViewModel();
p.Categories = entities.ProductCategories.ToList();
return View(p);
}
My AddNewProductViewModel looks like this:
using AccessorizeForLess.Data;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Web;
namespace AccessorizeForLess.ViewModels
{
public class AddNewProductViewModel
{
public string Name { get; set; }
[DataType(DataType.MultilineText)]
public string Description { get; set; }
public decimal Price { get; set; }
public string AltText { get; set; }
public int Quantity { get; set; }
public HttpPostedFileBase Image { get; set; }
public int SelectedCategoryId {get;set;}
public List<ProductCategory> Categories { get; set; }
public ProductCategory Category { get; set; }
}
}
In my opinion:
<div class="form-group">
@Html.LabelFor(model => model.SelectedCategoryId, "Category",new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownListFor(model => model.SelectedCategoryId, new SelectList(Model.Categories, "CategoryId", "CategoryName"), "- Please Select -")
@Html.ValidationMessageFor(model => model.SelectedCategoryId)
</div>
</div>
Thanks for helping everyone :)
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First I would change your ViewModel to include SelectedCategoryId
, and I would change your options as Categories
.
Not seeing any code for yours get
, I use ProductCategory
something like the following:
public class ProductCategory {
public int Id {get;set;}
public string Name { get;set;}
}
Your razor mark will become:
<div class="form-group">
@Html.LabelFor(model => model.Categories, new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownListFor(model => model.SelectedCategoryId,
new SelectList(Model.Categories, "Id", "Name"), "- Please Select -")
@Html.ValidationMessageFor(model => model.Categories)
</div>
</div>
The first parameter is the selected category and your parameters are populated from Categories
.
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Use your controller to create a list, then call the list from the view.
Controller:
public static List<SelectListItem> GetDropDown()
{
List<SelectListItem> ls = new List<SelectListItem>();
lm = (call database);
foreach (var temp in lm)
{
ls.Add(new SelectListItem() { Text = temp.name, Value = temp.id });
}
return ls;
}
Call Dropdown:
@Html.DropDownListFor(x => x.Field, PathToController.GetDropDown())
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