'Object reference not set to an instance of an object' error from anonymous array

Question

InquiryOrder Model

public class InquiryOrder
{
    [Key]
    public int InquiryOrderId { get; set; }

    public string InquiryOrderName { get; set; }

    [ForeignKey("ProductType")]
    public int? ProductTypeId { get; set; }
    public virtual ProductType ProductType { get; set; }
}

ProductType Model

public class ProductType
{
    [Key]
    public int ProductId { get; set; }

    [StringLength(100, ErrorMessage = "Must be less than 100 charcters", MinimumLength = 1)]
    [Required(ErrorMessage = "Required")]
    public string ProductTypeName { get; set; }

    public virtual List<InquiryOrder> inquiryOrders { get; set; }
}

InquiryOrder Controller

var displayedInquiryOrders = filteredInquiryOrders.Skip(iDisplayStart).Take(iDisplayLength);
        var result = from c in displayedInquiryOrders .AsEnumerable()
                      select new[] { 
                                Convert.ToString(c.InquiryOrderId),
                                c.InquiryOrderName,
                                c.ProductType.ProductTypeName,
                            };

Here from c.ProductType.ProductTypeName, im getting this error Object reference not set to an instance of an object. Pls help me to solve this. Thanks!

http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it — Nitin Varpe, Jan 14 '16 at 12:04
Well, what do you think could be `null` in `c.ProductType`? You are the only one who can run & debug the code. — Gert Arnold, Jan 14 '16 at 12:08

score 4 · Accepted Answer · answered Jan 14 '16 at 12:03

4

Here

new[] { 
                            Convert.ToString(c.InquiryOrderId),
                            c.InquiryOrderName,
                            c.ProductType.ProductTypeName,
                        };

Either:

c is null
c.ProductType is null

answered Jan 14 '16 at 12:03

Thanks!. yes i have null values in table and that occurred this error. But how can i adjust this array such that it accepts null values from database? – Isuru Jan 18 '16 at 03:30

score 0 · Answer 2 · answered Jan 14 '16 at 12:11

0

You need to add some NullReference controls. Pls try this:

           select new[]{ 
                            Convert.ToString(c?.InquiryOrderId),
                            c?.InquiryOrderName,
                            c?.ProductType?.ProductTypeName,
                        };

answered Jan 14 '16 at 12:11

Alper Tunga Arslan

569
3
10

1

Please also note that this works only in C#6 or above. – Sweeper Jan 14 '16 at 12:12
You are right. Sorry, i forgot this explanation. – Alper Tunga Arslan Jan 14 '16 at 12:15

'Object reference not set to an instance of an object' error from anonymous array

2 Answers2