Can a WCF Service return a Datatable ??

Question

The snippet shown below is not working ??? Why is it 
namespace MLA_CRM_Service
    [DataContract]
    public class MLAContact : DataTable  //(Cant i do this ?)
        [DataMember]
        private string MLAMemberType;
        [DataMember]
        private string MLAMemberNo ;
        [DataMember]
        private string fullName;
        [DataMember]
        private string companyName;
        [DataMember]
        private string addressLine1;
        [DataMember]
        private string addressLine2;
        [DataMember]
        private string suburb;
        [DataMember]
        private string state;
        [DataMember]
        private string postCode;
        [DataMember]
        private string country;
        [DataMember]
        private string emailAddress;
        [DataMember]
        public string _MLAMemberType
            get;
            set;
        [DataMember]
        public string _MLAMemberNo
            get;
            set;
        [DataMember]
        public string FullName
            get;
            set;
        [DataMember]
 .// All Getters and setter are implemented 
        [DataMember]
        public string EmailAddress
            get;
            set;
 public MLAContact()
            this.Columns.Add(new DataColumn("MLAMemberType", typeof(string)));
            this.Columns.Add(new DataColumn("MLAMemberNo", typeof(string)));
            this.Columns.Add(new DataColumn("FullName", typeof(string)));
            this.Columns.Add(new DataColumn("CompanyName", typeof(string)));
            this.Columns.Add(new DataColumn("AddressLine1", typeof(string)));
            this.Columns.Add(new DataColumn("AddressLine2", typeof(string)));
            this.Columns.Add(new DataColumn("Suburb", typeof(string)));
            this.Columns.Add(new DataColumn("State", typeof(string)));
            this.Columns.Add(new DataColumn("PostCode", typeof(string)));
            this.Columns.Add(new DataColumn("Country", typeof(string)));
            this.Columns.Add(new DataColumn("EmailAddress", typeof(string)));
public DataRow AddRows(usp_SecondaryContactCollectionResult content) {
DataRow dr = this.NewRow(); dr["FullName"] = content.FullName.ToString();
dr["EmailAddress"] = content.emailaddress.ToString(); return dr;
public DataRow AddRows(usp_GetUserDetailsResult content) {
DataRow dr = this.NewRow(); dr["MLAMemberType"] = content.MLAMemberType;
dr["MLAMemberNo"] = content.MemberNumber;
dr["FullName"] = content.FullName;
dr["CompanyName"] = content.CompanyName;
dr["AddressLine1"] = content.AddressLine1;
dr["AddressLine2"] = content.AddressLine2;
dr["Suburb"] = content.Suburb;
dr["State"] = content.State;
dr["PostCode"] = content.PostCode;
dr["Country"] = content.Country;
dr["EmailAddress"] = content.emailaddress;
return dr;
Now the Service method implementation
public DataTable SecondaryContactCollection(int contactID, string token)
            try
                using (ContactDataContext = new MLAWebUsers_ContactsDataContext())
                    MLAContact mlaContact = new MLAContact();
                    DataTable dt = new MLAContact();
                   var container = ContactDataContext.usp_SecondaryContactCollection(contactID, token);
                    foreach (usp_SecondaryContactCollectionResult item in container)
                        dt.ImportRow( mlaContact.AddRows(item));
                    return dt;
            catch (Exception ex)
                throw ex;
Now the above code compiles perfectly .... But when i try to consume it in the client side ...
Exception is thrown 
Client side Code
protected void Page_Load(object sender, EventArgs e)
                DataTable dt = new DataTable();
                int i = 0;
                int a = 145417;
                string x = "A1F3CKeog&";
                MLA_CRM_ServicesClient clientEndPoint = new MLA_CRM_ServicesClient("BasicHttpBinding_IMLA_CRM_Services");
                dt = clientEndPoint.SecondaryContactCollection(a, x);
                i = dt.Rows.Count;
                Label1.Text = i.ToString();
The above line that is Bold in the client code, thats the place where the exception is thrown .... Have gone through the stack trace still not able to fix it !!!!
Regards,
Chandra.

Answer 1

you have two options
Option 1
Simply give your Table a name. If you don’t,it will block the client and time out which throws an unexpected exception.
DataTable dt = new MLAContact("SomeTableName");
Option 2
Create a dataset and Add your datatable and return datatable from dataset i.e
DataTable dt = new MLAContact();
DataSet ds =
new
DataSet
ds.Tables.Add(dt);
return
ds.Tables[0];
Reason:
The root reason is the DataTable inside a dataset inherits a schema namespace from the dataSet, but an independent datatable has an empty namespace (unless we change it).  Data cannot be changed between two dataTables with different namespace.
If
this helps do not forget to mark it as Answer
  I would recomend you to go ahead with Option 1. And share your views.
Lingaraj Mishra