Error: "Cannot implicitly convert type"

Question

I am working on one project and I have a question regarding the converting type. I want to create simple search for my project, but it keeps asking about Ienumerable type, which honestly I did not understand. Please help.

The problem:

Error 1 Cannot implicitly convert type 'System.Collections.Generic.IEnumerable' to 'PagedList.IPagedList'. An explicit conversion exists (are you missing a cast?) C:\Users\Asus\Documents\Visual Studio 2012\Projects\Nordstromapp\Nordstromapp\Controllers\ProductController.cs 38 24 Nordstromapp

My code:

{
    NordstromEntities _db;

    public ProductController()
    {
        _db = new NordstromEntities();
    }
    //
    // GET: /Product/

    public ActionResult Index(string sortOrder, string CurrentSort, int? page, string searchString)
    {
        int pageSize = 10;
    int pageIndex = 1;
    pageIndex = page.HasValue ? Convert.ToInt32(page) : 1;

    ViewBag.CurrentSort = sortOrder;

    sortOrder = String.IsNullOrEmpty(sortOrder) ? "ID" : sortOrder;

    IPagedList<Product_list> products = null;



    if (!String.IsNullOrEmpty(searchString))
    {
        products = products.Where(m => m.ID.ToUpper().Contains(searchString.ToUpper())
                               || m.Product_name.ToUpper().Contains(searchString.ToUpper()));
    }

    switch (sortOrder)
    {
        case "ID":
            if(sortOrder.Equals(CurrentSort))  
                products = _db.Product_list.OrderByDescending
                        (m => m.ID).ToPagedList(pageIndex, pageSize);   
            else
                products = _db.Product_list.OrderBy
                        (m => m.ID).ToPagedList(pageIndex, pageSize);   
            break;

        case "Product_name":
            if (sortOrder.Equals(CurrentSort))
                products = _db.Product_list.OrderByDescending
                        (m => m.Product_name).ToPagedList(pageIndex, pageSize);
            else
                products = _db.Product_list.OrderBy
                        (m => m.Product_name).ToPagedList(pageIndex, pageSize);
            break;

        case "Product_category":
            if (sortOrder.Equals(CurrentSort))
                products = _db.Product_list.OrderByDescending
                        (m => m.Product_category).ToPagedList(pageIndex, pageSize);
            else
                products = _db.Product_list.OrderBy
                        (m => m.Product_category).ToPagedList(pageIndex, pageSize);
            break;

        case "Price":
            if (sortOrder.Equals(CurrentSort))
                products = _db.Product_list.OrderByDescending
                        (m => m.Price).ToPagedList(pageIndex, pageSize);
            else
                products = _db.Product_list.OrderBy
                        (m => m.Price).ToPagedList(pageIndex, pageSize);
            break;


    }
    return View(products);
}

Answer 1

While products is indeed of type IPagedList<Product_List>, the call to .Where() on an instance of IPagedList<Product_List> returns an IEnumerable<Product_List>, which can't be implicitly converted. Notice how you perform conversions here:

products = _db.Product_list.OrderByDescending(m => m.ID)
                           .ToPagedList(pageIndex, pageSize);

You just need to perform the same conversion after your .Where() call:

products = products.Where(m => m.ID.ToUpper().Contains(searchString.ToUpper()) ||
                               m.Product_name.ToUpper().Contains(searchString.ToUpper()))
                   .ToPagedList(pageIndex, pageSize);