asp.net mvc - how to write method for mapping lists in viewmodel and display collection in razor view -

i trying display collection of products (using view model) in pro() method

models

public class product {     public product() { this.adddate = datetime.now; }      public int productid { get; set; }     [required(errormessage = "enter product name")]     [stringlength(160)]     public string productname { get; set; }     [required(errormessage = "enter product description")]     [stringlength(500)]     public string productdescription { get; set; }     public datetime adddate { ; private set; }     [required(errormessage = "select category")]     [display(name="category")]     public string category { get; set; }     [required(errormessage = "location")]     public bool location { get; set; } }  public class productpicture {     public int id { get; set; }     public int productid { get; set; }     [required(errormessage ="please select picture")]     public string pictureurl { get; set; } } 

view model

public class productviewmodel {     public int productid { get; set; }     public string productname { get; set; }     [required(errormessage = "enter product description")]     [stringlength(500)]     public string productdescription { get; set; }     public datetime adddate { get; private set; }     [required(errormessage = "select category")]     [display(name = "category")]     public string category { get; set; }     [required(errormessage = "location")]     public bool location { get; set; }     public ienumerable<productpicture> productpictures { get; set; } } 

controller method

 public actionresult pro()  {           productviewmodel product = new productviewmodel();      var pro = db.products.tolist();      if (pro != null)      {          product.productname = pro.productname;          product.productdescription = pro.productdescription;          product.payextra = pro.payextra;          product.location = pro.location;            product.productpictures = db.productpictures.where(m => m.productid == pro.select(m=>m.productid));             }      return view(product); } 

currently throwing following exception

since trying map complete list single object "=" operator can not applied int ienumerable. logically doing wrong , please me select current id ienumerable , map current productpicture list , @ last create collection of same viewmodel can displayed in view.

you need change method project collection of product collection of productviewmodel , return view.

public actionresult pro() {     var pictures = db.productpictures;     var model = db.products.select(p => new productviewmodel     {         productname = p.productname,         productdescription = p.productdescription,         ....         productpictures = pictures.where(x => x.productid == p.id)     };     return view(model); } 

then in view

@model ienmerable<productviewmodel> <table>     <thead>         <tr>             <th>@html.displaynamefor(m => m.productname)</th>             ....         </tr>     </thead>     <tbody>         @foreach(var product in model)         {             <tr>                 <td>@html.displayfor(m => product.productname)</td>                 .... 

side note: recommend change name of method index() means user can navigate using .../products (assuming using default routing), or @ least name indicates displaying products (the current url ../products/pro not convey useful meaning user)