How to parse JSON from String?

How to parse JSON string that can be one of two different strongly typed objects?

• Background: I'm invoking a web service method which returns a JSON string. This string can be of type ASConInfo or ASErrorResponse. Question: Using the DataContractJsonSerializer, how can I convert the returned JSON string to one of those objects? Thanks in advance I have tried the following technique, but it does not work: public static object test(string inputString) { object obj = null; using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(inputString))) { DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(object)); obj = ser.ReadObject(ms) as object; } return obj; } [WebMethod] public string TypeChecker() { string str = "{\"Error\":191,\"ID\":\"112345678921212\",\"Length\":15}"; //string strErro = ""; object a = test(str); if (a is ASResponse) { return "ASResponse"; } if (a is ASErrorResponse) { return "ASErrorResponse"; } return "Nothing"; } [DataContract] public class ASResponse { #region Attribut(s) private string idField; private int lengthField; private int callHomeField; private SlinkyRequest slinkyRequestField; private AssociationServeResponseMessage responseMessageField; private int errorField; private string slinkyIDField; private int tokenLengthField; private string tokenField; private SlinkyInfo slinkyInfoField; private string slinkyIPAddressField; private string videoSizeField; private string slinkyStreamingField; private int slinkyMaxFrameField; private int maxVideoRateField; private int maxAudioRateField; private AudioType audioTypeField; #endregion #region Constructor(s) /// <summary> /// /// </summary> public ASResponse() { } #endregion #region Property(ies) [DataMember] /// <summary> /// /// </summary> public string ID { get { return idField; } set { idField = value; } } [DataMember] /// <summary> /// /// </summary> public int Length { get { return this.lengthField; } set { this.lengthField = value; } } [DataMember] /// <summary> /// /// </summary> public int CallHome { get { return callHomeField; } set { if (this.callHomeField < StaticValues.callHomeMinValue || this.callHomeField > StaticValues.callHomeMaxValue) { throw new ArgumentOutOfRangeException("CallHome value is out of Range."); } callHomeField = value; } } [DataMember] /// <summary> /// /// </summary> public SlinkyRequest SlinkyRequest { get { return slinkyRequestField; } set { slinkyRequestField = value; } } public AssociationServeResponseMessage ResponseMessage { get { return responseMessageField; } set { responseMessageField = value; } } public int Error { get { return errorField; } set { errorField = value; } } [DataMember] /// <summary> /// /// </summary> public string SlinkyID { get { return slinkyIDField; } set { slinkyIDField = value; } } [DataMember] /// <summary> /// /// </summary> public int TokenLength { get { return tokenLengthField; } set { tokenLengthField = value; } } [DataMember] /// <summary> /// /// </summary> public string Token { get { return tokenField; } set { tokenField = value; } } [DataMember] /// <summary> /// /// </summary> public SlinkyInfo IsSlinkyInfoEnabled { get { return slinkyInfoField; } set { slinkyInfoField = value; } } [DataMember] /// <summary> /// /// </summary> public string SlinkyIPAddress { get { return slinkyIPAddressField; } set { slinkyIPAddressField = value; } } [DataMember] /// <summary> /// /// </summary> public string VideoSize { get { return videoSizeField; } set { videoSizeField = value; } } [DataMember] /// <summary> /// /// </summary> public string Streaming { get { return slinkyStreamingField; } set { slinkyStreamingField = value; } } [DataMember] /// <summary> /// /// </summary> public int MaxFrame { get { return slinkyMaxFrameField; } set { slinkyMaxFrameField = value; } } [DataMember] /// <summary> /// /// </summary> public int MaxVideoRate { get { return maxVideoRateField; } set { maxVideoRateField = value; } } [DataMember] /// <summary> /// /// </summary> public int MaxAudioRate { get { return maxAudioRateField; } set { maxAudioRateField = value; } } [DataMember] /// <summary> /// /// </summary> public AudioType AudioType { get { return audioTypeField; } set { audioTypeField = value; } } /// <summary> /// /// </summary> public Dictionary<string, string> Extra_Metadata { get; set; } #endregion } /// <summary> /// /// </summary> [DataContract] public class ASErrorResponse { /// <summary> /// /// </summary> [DataMember] public int Length { get; set; } /// <summary> /// /// </summary> [DataMember] public string ID { get; set; } /// <summary> /// /// </summary> [DataMember] public int Errorv2 { get; set; } /// <summary> /// /// </summary> /// <param name="item"></param> /// <returns></returns> public static string FromASErrorResponseToJson(ASErrorResponse item) { string strJson = string.Empty; DataContractJsonSerializer dcjs = new DataContractJsonSerializer(typeof(ASErrorResponse)); MemoryStream ms = new MemoryStream(); dcjs.WriteObject(ms, item); strJson = Encoding.UTF8.GetString(ms.ToArray()); return strJson; } }

• Answer:

  Not the best solution but this should at least work: public static object test(string inputString) { object obj = null; using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(inputString))) { try { DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(ASErrorResponse)); obj = ser.ReadObject(ms) as ASErrorResponse; } catch (SerializationException) { } } using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(inputString))) { try { DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(ASResponse)); obj = ser.ReadObject(ms) as ASResponse; } catch (SerializationException) { } } return obj; }