Can't convert from model to viewmodel, using AutoMapper asp.net core - asp.net

Question

I am using Auto mapper to map between modelviews and models. I have followed the same steps given by the Auto mapper documentation and still can't find where the issue is.
public class RegisterStaffViewModel
{
public int Id { get; set; }
[Required(ErrorMessage = "StaffName Required")]
public string StaffName { get; set; }
[Required(ErrorMessage = "Gender Required")]
public string Gender { get; set; }
[Required(ErrorMessage = "Address Required")]
public string Address { get; set; }
[Required(ErrorMessage = "StaffCode Required")]
public string StaffCode { get; set; }
[DisplayName("Department")]
[Required(ErrorMessage = "Department is Required")]
public int? DepartmentId { get; set; }
public string CardNo { get; set; }
[Required(ErrorMessage = "Mobileno Required")]
[RegularExpression(#"^(\d{10})$", ErrorMessage = "Wrong Mobileno")]
public string MobileNo { get; set; }
[Required(ErrorMessage = "EmailID Required")]
[RegularExpression(#"^([a-zA-Z0-9_\-\.]+)#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$", ErrorMessage = "Please enter a valid e-mail adress")]
public string Email { get; set; }
public DateTime EntryDate { get; set; }
[Display(Name = "Position")]
[Required(ErrorMessage = "Position is Required")]
public int? PositionId { get; set; }
[Display(Name = "Staff Type")]
[Required(ErrorMessage = "Staff Type is Required")]
public int? StaffTypeId { get; set; }
public string CardIdNo { get; set; }
public bool? IsDeleted { get; set; }
public bool? IsUpdated { get; set; }
public string CreatedBy { get; set; }
public string UpdatedBy { get; set; }
public string DeletedBy { get; set; }
public string Remarks { get; set; }
public virtual ApplicationUser CreatedByNavigation { get; set; }
public virtual ApplicationUser DeletedByNavigation { get; set; }
public virtual Departments Department { get; set; }
public virtual Positions Position { get; set; }
public virtual StaffTypes StaffType { get; set; }
public virtual ApplicationUser UpdatedByNavigation { get; set; }
public virtual ICollection<AttendanceRecorderViewModel> AttendanceRecorder { get; set; }
public virtual ICollection<ManageLeavesViewModel> ManageLeaves { get; set; }
public virtual ICollection<RegisterDevicesViewModel> RegisterDevices { get; set; }
}
=============================================================================================
public partial class RegisterStaffs
{
public int Id { get; set; }
public string StaffName { get; set; }
public string Gender { get; set; }
public string Address { get; set; }
public string StaffCode { get; set; }
public int? DepartmentId { get; set; }
public string CardNo { get; set; }
public string MobileNo { get; set; }
public string Email { get; set; }
public DateTime EntryDate { get; set; }
public int? PositionId { get; set; }
public int? StaffTypeId { get; set; }
public string CardIdNo { get; set; }
public bool? IsDeleted { get; set; }
public bool? IsUpdated { get; set; }
public string CreatedBy { get; set; }
public string UpdatedBy { get; set; }
public string DeletedBy { get; set; }
public string Remarks { get; set; }
public virtual ApplicationUser CreatedByNavigation { get; set; }
public virtual ApplicationUser DeletedByNavigation { get; set; }
public virtual Departments Department { get; set; }
public virtual Positions Position { get; set; }
public virtual StaffTypes StaffType { get; set; }
public virtual ApplicationUser UpdatedByNavigation { get; set; }
public virtual ICollection<AttendanceRecorder> AttendanceRecorder { get; set; }
public virtual ICollection<ManageLeaves> ManageLeaves { get; set; }
public virtual ICollection<RegisterDevices> RegisterDevices { get; set; }
}
============================================================================================
public interface IMapperConfig
{
IMapper CreateMapper();
}
public class MapperConfig : IMapperConfig
{
public IMapper CreateMapper()
{
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<RegisterStaffs, RegisterStaffViewModel>();
cfg.CreateMap<AttendanceRecorder, AttendanceRecorderViewModel>();
cfg.CreateMap<ManageLeaves, ManageLeavesViewModel>();
cfg.CreateMap<RegisterDevices, RegisterDevicesViewModel>();
});
return config.CreateMapper();
}
}
==========================================================================================
public async Task<ReturnResult<List<RegisterStaffViewModel>>> GetAllEmployees()
{
var result = new ReturnResult<List<RegisterStaff>>();
try
{
var employees = await context.RegisterStaffs.Where(x => (bool)!x.IsDeleted).OrderByDescending(x => x.EntryDate).AsNoTracking().ToListAsync();
// **here is the error**
result.Success(mapper.Map<List<RegisterStaffs>, List<RegisterStaffViewModel>>(employees));
}
catch(Exception ex)
{
}
return result;
}
============================================================================================
public class ReturnResult<T>
{
public ReturnResult()
{
ErrorList = new List<string>();
}
public bool IsSuccess { get; set; }
public HttpCode HttpCode { get; set; }
public T Data { get; set; }
public List<string> ErrorList { get; set; }
/// <summary>
/// Set success result with data
/// </summary>
/// <param name="Data"></param>
public void Success(T Data)
{
this.IsSuccess = true;
this.HttpCode = HttpCode.Success;
this.Data = Data;
}
/// <summary>
/// Set Server Error result with error message
/// </summary>
/// <param name="Error"></param>
public void ServerError(string Error)
{
this.IsSuccess = false;
this.HttpCode = HttpCode.ServerError;
this.ErrorList.Add(Error);
}
/// <summary>
/// Set Not Found result with error message
/// </summary>
/// <param name="Error"></param>
public void NotFound(string Error)
{
this.IsSuccess = false;
this.HttpCode = HttpCode.NotFound;
this.ErrorList.Add(Error);
}
}

Answer 1

I found the issue was here
var result = new ReturnResult<List<RegisterStaff>>();
i have changed it to
var result = new ReturnResult<List<RegisterStaffViewModel>>();