CODEWITHSUNDEEP
asp.netpaginationasp.net-core-mvcviewmodel
balance85
balance85

Reputation: 49

Cannot get pagination to work with view model asp.net core

i have checked out the other questions/answers on here but none seemed to work with my senario.

Here is my viewmodel:

 public class EmployeeListViewModel
    {
        public Employee Employee { get; set; }
        public PaginatedList<Employee> Employees { get; set; }
        public string Supervisor { get; set; }
    }

Top of view:

@model MMSystem.ViewModels.EmployeeListViewModel

Controller:

 public async Task<IActionResult> Index(string searchString, string currentFilter, int? pageNumber)
        {
            if (searchString != null)
            {
                pageNumber = 1;
            }
            else
            {
                searchString = currentFilter;
            }
            ViewData["CurrentFilter"] = searchString;


            var employeeList = (from e in _context.Employees
                                join s in _context.Employees on e.Id equals s.SupervisorId
                                select new { Employee = s, Supervisor = e.FullName });


            if (!String.IsNullOrEmpty(searchString))
            {
                employeeList = employeeList.Where(e => e.Employee.LastName.Contains(searchString)
                                       ||e.Employee.FirstName.Contains(searchString));
            }

            int pageSize = 3;
            return View(new EmployeeListViewModel { Employees = await PaginatedList<Employee>.CreateAsync(employeeList.AsNoTracking(), pageNumber ?? 1, pageSize) });

        }

And this is my error:

error

I have been trying everything to get it to work, but there seems to always be conversion or type conflict issues. (Note: everything worked fine prior to trying to add pagination)

Upvotes: 0

Views: 472

Answers (1)

Fei Han
Fei Han

Reputation: 27825

Based on your code, we can find that your code snippet (as below) return a list of anonymous objects which contains Employee and Supervisor properties.

var employeeList = (from e in _context.Employees join s in _context.Employees on e.Id equals s.SupervisorId select new { Employee = s, Supervisor = e.FullName });

And at this code snippet await PaginatedList<Employee>.CreateAsync(employeeList.AsNoTracking(), pageNumber ?? 1, pageSize), it can not explicitly convert anonymous object list to System.Linq.IQueryable, which causes the issue.

cannot convert from 'System.Linq.IQueryable<<anonymous type: MMSystem.Models.Employee Employee, string Supervisor>>' to 'System.Linq.IQueryable<MMSystem.Models.Employee>'

To fix it, you can try modify the code like below.

return View(new EmployeeListViewModel { Employees = await PaginatedList<Employee>.CreateAsync(employeeList.Select(s=>s.Employee).AsNoTracking(), pageNumber ?? 1, pageSize) });

Besides, you can refer to this tutorial with example that shows how to implement paging etc functionality.

Upvotes: 1

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