在本篇文章上一部分Order Processing的例子中，我们看到原本已Collection形式定义的DetailList属性（public IList<TDetail> DetailList），在Data Contract中却以Array的方式体现（public OrderDetail[] DetailList）。我们现在就来详细地讨论一下基于Collection & Dictionary 的Data Contract。
Data Contract for Collection
我们照例用例子来说明问题，在这里我们创建一个批量处理Order的Service，于是我们创建了一个OrderCollection Type:
namespace
Artech.SpecialDataContract.Contract
{
[DataContract] public class Order
{ [DataMember] public Guid OrderID { get; set; } [DataMember] public DateTime OrderDate { get; set; }
} public class OrderCollection : List<Order> { }
}
下面是Service Contract的定义：
namespace
Artech.SpecialDataContract.Contract
{ [ServiceContract] public interface IOrderManager { [OperationContract(Name = "ProcessWithCollection")] void Process(OrderCollection orders);}
面是OrderCollection 在XSD中的呈现：
<?
xml version="1.0" encoding="utf-8"
?>
<
xs:schema
elementFormDefault
="qualified"
targetNamespace
="http://schemas.datacontract.org/2004/07/Artech.SpecialDataContract.Contract"
xmlns:xs
="http://www.w3.org/2001/XMLSchema"
xmlns:tns
="http://schemas.datacontract.org/2004/07/Artech.SpecialDataContract.Contract"
xmlns:ser
="http://schemas.microsoft.com/2003/10/Serialization/"
>
<
xs:import
schemaLocation
="http://artech/Artech.SpecialDataContract/OrderManagerService.svc?xsd=xsd1"
namespace
="http://schemas.microsoft.com/2003/10/Serialization/"
/>
<
xs:complexType
name
="ArrayOfOrder"
>
<
xs:sequence
>
<
xs:element
minOccurs
="0"
maxOccurs
="unbounded"
name
="Order"
nillable
="true"
type
="tns:Order"
/>
</
xs:sequence
>
</
xs:complexType
>
<
xs:element
name
="ArrayOfOrder"
nillable
="true"
type
="tns:ArrayOfOrder"
/>
<
xs:complexType
name
="Order"
>
<
xs:sequence
>
<
xs:element
minOccurs
="0"
name
="OrderDate"
type
="xs:dateTime"
/>
<
xs:element
minOccurs
="0"
name
="OrderID"
type
="ser:guid"
/>
</
xs:sequence
>
</
xs:complexType
>
<
xs:element
name
="Order"
nillable
="true"
type
="tns:Order"
/>
</
xs:schema
>
加上通过Add Service Reference默认生成的Class，我们可以很清楚地看出Collection是以Array的形式呈现的（Artech.SpecialDataContract.Client.OrderManagerService.Order[] orders）：
[System.CodeDom.Compiler.GeneratedCodeAttribute(
"
System.ServiceModel
"
,
"
3.0.0.0
"
)] [System.ServiceModel.ServiceContractAttribute(ConfigurationName
=
"
OrderManagerService.IOrderManager
"
)]
public
interface
IOrderManager
{ [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/IOrderManager/ProcessWithCollection", ReplyAction="http://tempuri.org/IOrderManager/ProcessWithCollectionResponse")] void ProcessWithCollection(Artech.SpecialDataContract.Client.OrderManagerService.Order[] orders);}
因为Array相对很Common的数据类型，基本上所有的厂商均提供了对Array的支持，这也是WCF在通过Add Service Reference生成Client端代码的时候，会生成Array的原因。不过并不是我们只有唯一的选择，事实上VS为此提供了扩展，允许我们对于基于Collection 的Data Contract生成我们需要的各种类型，我们只需要在Add Service Reference的时候选择“Configure Service Reference”进行相应的配置：
通过上面的截图，我们发现在Collection Type一项我们有若干选项，我们可以选择我们希望生成的数据类型：Array，ArrayList，LinkedList，Generic List，Collection和BindingList。
Data Contract for Dictionary
前面的内容，我们分别讨论了基于Generic和Collection的Data Contract，接下来，我们来讨论最后一个特殊的数据类型的Data Contract：Dictionary。
延续上面的Order Batch Processing的例子，不过我们现在处理的不是一个OrderCollection对象，而是一个Dictionary对象，线面是Service Contract和Order的定义：
namespace
Artech.SpecialDataContract.Contract
{ [ServiceContract] public interface IOrderManager { [OperationContract(Name = "ProcessWithCollection")] void Process(OrderCollection orders); [OperationContract(Name = "ProcessWithDictionary")] void Process(IDictionary<Guid, Order> orders); }}
[DataContract]
public
class
Order
{ [DataMember] public Guid OrderID { get; set; } [DataMember] public DateTime OrderDate { get; set; } }
闲话少说，我们来看XSD：
<?
xml version="1.0" encoding="utf-8"
?>
<
xs:schema
elementFormDefault
="qualified"
targetNamespace
="http://schemas.microsoft.com/2003/10/Serialization/Arrays"
xmlns:xs
="http://www.w3.org/2001/XMLSchema"
xmlns:tns
="http://schemas.microsoft.com/2003/10/Serialization/Arrays"
xmlns:ser
="http://schemas.microsoft.com/2003/10/Serialization/"
>
<
xs:import
schemaLocation
="http://artech/Artech.SpecialDataContract/OrderManagerService.svc?xsd=xsd1"
namespace
="http://schemas.microsoft.com/2003/10/Serialization/"
/>
<
xs:import
schemaLocation
="http://artech/Artech.SpecialDataContract/OrderManagerService.svc?xsd=xsd2"
namespace
="http://schemas.datacontract.org/2004/07/Artech.SpecialDataContract.Contract"
/>
<
xs:complexType
name
="ArrayOfKeyValueOfguidOrder_SkVQi6O3"
>
<
xs:annotation
>
<
xs:appinfo
>
<
IsDictionary
xmlns
="http://schemas.microsoft.com/2003/10/Serialization/"
>
true
</
IsDictionary
>
</
xs:appinfo
>
</
xs:annotation
>
<
xs:sequence
>
<
xs:element
minOccurs
="0"
maxOccurs
="unbounded"
name
="KeyValueOfguidOrder_SkVQi6O3"
>
<
xs:complexType
>
<
xs:sequence
>
<
xs:element
name
="Key"
type
="ser:guid"
/>
<
xs:element
name
="Value"
nillable
="true"
type
="q1:Order"
xmlns:q1
="http://schemas.datacontract.org/2004/07/Artech.SpecialDataContract.Contract"
/>
</
xs:sequence
>
</
xs:complexType
>
</
xs:element
>
</
xs:sequence
>
</
xs:complexType
>
<
xs:element
name
="ArrayOfKeyValueOfguidOrder_SkVQi6O3"
nillable
="true"
type
="tns:ArrayOfKeyValueOfguidOrder_SkVQi6O3"
/>
</
xs:schema
>
Data Contract的名称为ArrayOfKeyValueOfguidOrder_SkVQi6O3=ArrayOfKeyValueOf+guid（Key的类型）+Order（Value）+_SkVQi6O3（Hash Value）。从该XSD的结构我们不难看出，只是一个数组，每个元素为Key-Value pair。
我们照例看看通过Add Service Reference方式生成的Client端code中的对应的定义：
[System.CodeDom.Compiler.GeneratedCodeAttribute(
"
System.ServiceModel
"
,
"
3.0.0.0
"
)] [System.ServiceModel.ServiceContractAttribute(ConfigurationName
=
"
OrderManagerService.IOrderManager
"
)]
public
interface
IOrderManager
{ [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/IOrderManager/ProcessWithDictionary", ReplyAction="http://tempuri.org/IOrderManager/ProcessWithDictionaryResponse")] void ProcessWithDictionary(System.Collections.Generic.Dictionary<System.Guid, Artech.SpecialDataContract.Client.OrderManagerService.Order> orders); }
生成的是一个System.Collections.Generic.Dictionary类型。同Collection一样，也依然可以有多种选择：
