how to use linq for showing image in webgrid [duplicate] - asp.net-mvc

Question

in web-grid i can not use navigation properties between my classes(products and productimages classes). for example i have used below code in web grid:
grid.Column("", "test",item=> (item.ProductImages.First().Id)+(item.Price))
but i got error:
'System.Collections.Generic.HashSet<WebStore.Models.ProductImage>' does not contain a definition for 'First'
my total code is like below:
#model IEnumerable<WebStore.Models.Product>
#using System.Linq;
#{
var grid = new WebGrid(source: Model, rowsPerPage: 5,ajaxUpdateContainerId:"divGrid");
}
#grid.GetHtml(tableStyle: "gridStyle", headerStyle: "gridHeader", rowStyle: "gridRow", alternatingRowStyle: null,htmlAttributes:new{Id="divGrid"},
columns: new WebGridColumn[] {
grid.Column("ProductName", "Product Name"),
grid.Column("Price", "Price"),
grid.Column("Description", "Description"),
grid.Column("CategoryName","Category Name",x=>x.Category.CategoryName),
grid.Column("", "test",item=> (item.ProductImages.First().Id)+(item.Price)),
grid.Column("","",x=>Html.ActionLink("Edit", "Edit", new{id=x.Id})),
grid.Column("","",x=>Html.ActionLink("Details", "Details", new{id=x.Id})),
grid.Column("","",x=>Html.ActionLink("Delete", "Delete", new{id=x.Id}))
}
)
this is my index view:
#model IEnumerable<WebStore.Models.Product>
#using System.Linq
#{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_LayoutCategory.cshtml";
}
<br/>
<p>
#Html.ActionLink("Create New", "Create")
</p>
<div id="divGrid">
#{ Html.RenderPartial("_ProductTitle", Model); }
</div>
this is my RenderPartial that use web grid before i posted:
#model IEnumerable<WebStore.Models.Product>
#using System.Linq
#ViewBag.test
#{
var grid = new WebGrid(source: Model, rowsPerPage: 5,ajaxUpdateContainerId:"divGrid");
}
#grid.GetHtml(tableStyle: "gridStyle", headerStyle: "gridHeader", rowStyle: "gridRow", alternatingRowStyle: null,htmlAttributes:new{Id="divGrid"},
columns: new WebGridColumn[] {
grid.Column("ProductName", "Product Name"),
grid.Column("Price", "Price"),
grid.Column("Description", "Description"),
grid.Column("CategoryName","Category Name",x=>x.Category.CategoryName),
grid.Column("", "test",item=>(int) (item.ProductImages.FirstOrDefault().Id)+(int)(item.Price)),
grid.Column("","",x=>Html.ActionLink("Edit", "Edit", new{id=x.Id})),
grid.Column("","",x=>Html.ActionLink("Details", "Details", new{id=x.Id})),
grid.Column("","",x=>Html.ActionLink("Delete", "Delete", new{id=x.Id}))
}
)

Answer 1

It's because definition of First is available in System.Linq. So, you should have System.Linq in your razor page :
#using System.Linq;
if you are using Linq in multiple page, you can add System.Linq namespace in web.config so that you do not need to write above using in each page. You can add namespace in web.config in following configuration :
<system.web.webPages.razor>
<pages>
<namespaces>
<add namespace="System.Linq" />
</namespaces>
</pages>
</system.web.webPages.razor>

Answer 2

i got the answer of my question with below code from the net:
I followed your steps and test your code and the same error display. So I think the format in your code can not be used in webgrid. So I think about another way to meet your requirement: we need a ViewModel to display what you want to show in the View and search the first item in Controller then save as ViewModel and pass the ViewModel to View, then we do not need search in the View. Here I will show you the steps with my demo.
Now, we have two model Product and Quantity that one product has many quantities. We should create a ViewModel.
ViewModel.cs:
public class ViewModel
{
public string Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public long quan { get; set; }
}
We can initialize some data and search the first value of Quantity depend on Product in Controller and assign to the ViewModel.
InventoryController .cs:
public class InventoryController : Controller
public ActionResult WebgridSample()
{
ObservableCollection<Product> inventoryList =
new ObservableCollection<Product>();
inventoryList.Add(new Product
{
Id = "P101",
Name = "Computer",
Description = "All type of computers",
quantity = new List<Quantity>
{
new Quantity {QUAN = 100 },
new Quantity {QUAN = 200 },
new Quantity {QUAN = 300 }
}
});
inventoryList.Add(new Product
{
Id = "P102",
Name = "Laptop",
Description = "All models of Laptops",
quantity = new List<Quantity>
{
new Quantity {QUAN = 400 },
new Quantity {QUAN = 500 },
new Quantity {QUAN = 600 }
},
});
inventoryList.Add(new Product
{
Id = "P103",
Name = "Camera",
Description = "Hd cameras",
quantity = new List<Quantity>
{
new Quantity {QUAN = 700 },
new Quantity {QUAN = 800 },
new Quantity {QUAN = 900 }
}
});
IEnumerable<string> model = (from sig in inventoryList
select new ViewModel
{
Name = sig.Name,
Description = sig.Description,
quan = sig.quantity.FirstOrDefault(),
}).ToList();
return View(model);
}
We can call each parameters of ViewModel in webgrid without using First().
WebgridSample.cshtml:
<div id="gridContent">
#grid.GetHtml(tableStyle: "webGrid",
headerStyle: "header",
alternatingRowStyle: "alt",
selectedRowStyle: "select",
columns: grid.Columns(
grid.Column("Id", ),
grid.Column("Name", " Name"),
grid.Column("Description", "Description", style: "description"),
grid.Column("Quantity", "quan "</i>)
))