1 static void SystemTextJsonDemo()
 2         {
 3             var obj = new[]
 4             {
 5                 new
 6                 {
 7                     Id=1,
 8                     Name="Fred",
 9                     Age=10
10                 },
11                 new
12                 {
13                     Id=2,
14                     Name="Fred2",
15                     Age=20
16                 },
17                 new
18                 {
19                     Id=3,
20                     Name="Fred3",
21                     Age=30
22                 }
23             };
24             JsonSerializerOptions jso = new JsonSerializerOptions();
25             jso.WriteIndented = true;            
26             string jsonValue = JsonSerializer.Serialize(obj, typeof(object), jso);
27             File.WriteAllText("JsonText2.json", jsonValue);
28             Console.WriteLine(jsonValue);
29         }