WCF VS ASPNET WEB SERVICE

参看：

１，　http://keithelder.net/2008/10/17/WCF-vs-ASMX-WebServices/

２，　http://www.cnblogs.com/philzhou/archive/2010/08/11/wcf_vs_web_service.html

３，　http://www.bishoylabib.com/2009/08/comparing-asmx-and-wcf.html

要点：

旧的Web Service 仅能在 HTTP 环境下使用，非有比较多的限制条件; 

新的 WCF 几乎不限定使用条件，可在HTTP 及 TCP/IP 等

The development of web service with ASP.NET relies on defining data  and relies on the XmlSerializer to transform data to or from a service.

Key issues with XmlSerializer to serialize .NET types to XML 

• Only Public fields or Properties of .NET types can be translated into XML.
• Only the classes which implement IEnumerable interface.
• Classes that implement the IDictionary interface, such as Hash table can not be serialized.

The WCF uses the DataContractAttribute and DataMemeberAttribute to translate .NET FW types in to XML.

[DataContract] 
public class Item 
{ 
    [DataMember] 
    public string ItemID; 
    [DataMember] 
    public decimal ItemQuantity; 
    [DataMember] 
    public decimal ItemPrice;

}