How to concatanate the class fields in C#

 class Program
    {
        class CustomListItem
        {
            public string Property1 { get; set; }
            public string Property2 { get; set; }
        }
        static void Main(string[] args)
        {
            CustomListItem record = new CustomListItem();
            
            record.Property1 = "value1";
            record.Property2 = "value2"; 
            string compositeKey = string.Empty;
            StringBuilder sbKey = new StringBuilder(); 
            PropertyInfo[] fromFields = null; 
            fromFields = typeof(CustomListItem).GetProperties(); 
            foreach (PropertyInfo prop in fromFields) { 
                sbKey.Append(prop.GetValue(record,null));
            }
            compositeKey = sbKey.ToString(); 
            Console.WriteLine(compositeKey);
            Console.ReadLine();
        }
    }

                                              

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:

class Program
    {
        class CustomListItem
        {
            public string Property1 { get; set; }
            public string Property2 { get; set; } 
            public string CompositeKey { get; set; }
        } 
        static void Main(string[] args)
        {
            CustomListItem record = new CustomListItem();
            
            record.Property1 = "value1";
            record.Property2 = "value2"; 
            StringBuilder sbKey = new StringBuilder(); 
            PropertyInfo[] fromFields = null; 
            fromFields = typeof(CustomListItem).GetProperties(); 
            var filteredFromFields = from x in fromFields
                                     where (x.Name != "CompositeKey")
                                     select x; 
            foreach (var x in filteredFromFields) {  
                sbKey.Append(((PropertyInfo)x).GetValue(record,null));
            } 
            var compositeKey = (from x in fromFields
                           where (x.Name == "CompositeKey")
                           select x).First();
            
            ((PropertyInfo)compositeKey).SetValue(record, sbKey.ToString(), null); 
            Console.WriteLine(record.CompositeKey);
            Console.ReadLine();
        }
    }

                                              

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42: