c# - Can't return an object from my .Net Web Service -

here web service. builds , launches , can browse it. validatecoupon method works because returns int.

the problem getcouponinfo method. should return object of type coupon xml generates looks this:

using system; using system.collections.generic; using system.linq; using system.web; using system.web.services; using confignamespace; using utilsnamespace;  /// <summary> /// web services coupon processing in simgrocery /// </summary> [webservice(namespace = "http://tempuri.org/")] [webservicebinding(conformsto = wsiprofiles.basicprofile1_1)] // allow web service called script, using asp.net ajax, uncomment following line.  // [system.web.script.services.scriptservice] public class couponservice : system.web.services.webservice {      /// <summary>     /// summary description coupon     /// </summary>     public class coupon {         private list<coupondetail> mcoupondetails;         private string mcoupon;         private string mdescription;         private string mcouponsource;         private datetime mstartdate, mthroughdate;          // parameterless constructor required object serialized.         public coupon() { }          public coupon(string coupon, string description, string couponsource, datetime startdate, datetime throughdate) {             list<coupondetail> mcoupondetails = new list<coupondetail>();             mcoupon = coupon;             mdescription = description;             mcouponsource = couponsource;             mstartdate = startdate;             mthroughdate = throughdate;         }         public string coupon { { return mcoupon; } }         public string description { { return mdescription; } }         public string couponsource { { return mcouponsource; } }         public datetime startdate { { return mstartdate; } }         public datetime throughdate { { return mthroughdate; } }          public list<coupondetail> coupondetails {             { return mcoupondetails; }             set { mcoupondetails = value; }         }          public void addcoupondetail(coupondetail coupondetail) {             mcoupondetails.add(coupondetail);         }      }      public class coupondetail {         string mproduct;         double mamountoff;         int mpercentagediscount;         string mdiscounttype;          // parameterless constructor required object serialized.         public coupondetail() { }          public coupondetail(string product, double amountoff, int percentagediscount, string discounttype) {             mproduct = product;             mamountoff = amountoff;             mpercentagediscount = percentagediscount;             mdiscounttype = discounttype;         }         public string product { { return mproduct; } }         public double amountoff { { return mamountoff; } }         public int percentagediscount { { return mpercentagediscount; } }         public string discounttype { { return mdiscounttype; } }      }      public couponservice () {          //uncomment following line if using designed components          //initializecomponent();      }      [webmethod]     public string helloworld() {         return "hello world";     }     [webmethod]     public int validatecoupon(string coupon) {         int couponid = 0;         // (string ptarget, string pdomain, string pcriteria, string paggregate)         return couponid;     }     [webmethod]     public coupon getcouponinfo(int couponid) {         // todo: write         // use fgetcouponinfo table-valued function in sql server         coupon coupon = new coupon("xxxxx","test coupon","penny saver", convert.todatetime("1/1/2016"), convert.todatetime("12/31/2016"));          return coupon;     } } 

you getting nothing because properties except coupondetails coupon class readonly.

quote link :

if web service contains web method either accepts parameter or returns value object reference, , class definition of object contains read-only property, read-only property not available when build proxy assembly web service.

the workaround, if persist have readonly properties, implement setter throwing notimplementedexception

like 1 :

public datetime throughdate  {      { return mthroughdate; }      set { throw new notimplementedexception("cannot set read-only property 'throughdate '"); } }