Passing DataSet to WCF Service

Question

I am new to .NET. I am trying to pass the DataSet following way to WCFService.

public static System.Data.DataSet ds = new System.Data.DataSet();
wscfservice.wcftestfunction(string1, string2, ref ds);

in WSDL file, the type defined

ActualType xmlns="http://schemas.microsoft.com/2003/10/Serialization/" Name="DataSet" Namespace="http://schemas.datacontract.org/2004/07/System.Data"

If I don't use ref, I am getting the compilation error. After running the program, I am getting a null value.

Here are error and ds descriptions

Channel Obtaining the runtime type of a transparent proxy is not supported in this context. 

• ds {System.Data.DataSet} System.Data.DataSet CaseSensitive false bool Container null System.ComponentModel.IContainer DataSetName "NewDataSet" string
• DefaultViewManager {System.Data.DataViewManager} System.Data.DataViewManager DesignMode false bool EnforceConstraints true bool
• Events {System.ComponentModel.EventHandlerList} System.ComponentModel.EventHandlerList
• ExtendedProperties Count = 0 System.Data.PropertyCollection HasErrors false bool IsInitialized true bool
• Locale {en-US} System.Globalization.CultureInfo Namespace "" string Prefix "" string
• Relations {System.Data.DataRelationCollection.DataSetRelationCollection} System.Data.DataRelationCollection {System.Data.DataRelationCollection.DataSetRelationCollection} RemotingFormat Xml System.Data.SerializationFormat SchemaSerializationMode IncludeSchema System.Data.SchemaSerializationMode Site null System.ComponentModel.ISite
• Tables {System.Data.DataTableCollection} System.Data.DataTableCollection Count 0 int IsReadOnly false bool IsSynchronized false bool
• List Count = 0 System.Collections.ArrayList
• SyncRoot {System.Data.DataTableCollection} object {System.Data.DataTableCollection}
• Static members
• Non-Public members
• Results View Expanding the Results View will enumerate the IEnumerable

Answer 1

If you choose to (or must) use a DataSet, you need to set the Name property in order to ensure it serializes.

public static System.Data.DataSet ds = new System.Data.DataSet("MyDataSet");

From MSDN:

A name for the DataSet is required to ensure that the XML representation of the DataSet always has a name for the document element, which is the highest level element in a schema definition.