# System.Runtime.Serialization.Json

``` diff
+namespace System.Runtime.Serialization.Json {
+    public sealed class DataContractJsonSerializer {
+        public DataContractJsonSerializer(Type type);
+        public DataContractJsonSerializer(Type type, IEnumerable<Type> knownTypes);
+        public DataContractJsonSerializer(Type type, DataContractJsonSerializerSettings settings);
+        public DateTimeFormat DateTimeFormat { get; }
+        public EmitTypeInformation EmitTypeInformation { get; }
+        public ReadOnlyCollection<Type> KnownTypes { get; }
+        public int MaxItemsInObjectGraph { get; }
+        public bool SerializeReadOnlyTypes { get; }
+        public bool UseSimpleDictionaryFormat { get; }
+        public object ReadObject(Stream stream);
+        public void WriteObject(Stream stream, object graph);
+    }
+    public class DataContractJsonSerializerSettings {
+        public DataContractJsonSerializerSettings();
+        public DateTimeFormat DateTimeFormat { get; set; }
+        public EmitTypeInformation EmitTypeInformation { get; set; }
+        public bool IgnoreExtensionDataObject { get; set; }
+        public IEnumerable<Type> KnownTypes { get; set; }
+        public int MaxItemsInObjectGraph { get; set; }
+        public string RootName { get; set; }
+        public bool SerializeReadOnlyTypes { get; set; }
+        public bool UseSimpleDictionaryFormat { get; set; }
+    }
+}
```