How to: Define a Windows Communication Foundation Service Contract

• 1.Open Visual Studio 2012 as an administrator by right-clicking the program in the Start menu and selecting Run as administrator.

使用管理员权限打开VS2012

• 2.Create a WCF Service Library project by clicking the File menu and selecting New, Project. In the New Project dialog, on the left-hand side of the dialog expand Visual C# for a C# project or Other Languagesand then Visual Basic for a Visual Basic project. Under the language selected select WCF and a list of project templates will be displayed on the center section of the dialog. Select WCF Service Library, and type GettingStartedLib in the Name textbox and GettingStarted in the Solution name textbox at the bottom of the dialog.

创建一个wcf服务的类库，在新建项目的对话框中，左边选择C#，然后选择wcf，然后选择wcf服务类库。项目名为GettingStartedLib ，解决方案名为GettingStarted 

• 3.Visual Studio will create the project which contains 3 files: IService1.cs (or IService1.vb), Service1.cs (or Service1.vb), and App.config. The IService1 file contains a default service contract. The Service1 file contains a default implementation of the service contract. The App.config file contains configuration needed to load the default service with the Visual Studio WCF Service Host. For more information about the WCF Service Host tool, see WCF Service Host (WcfSvcHost.exe)

VS会创建一个包含3个文件的项目：文件分别是IService1.cs,Service1.cs ,App.config。 IService1文件包含了默认的服务契约，Service1文件包含了实现了默认服务契约的代码。配置文件包含了加载默认服务所需要的配置

• 4.Open the IService1.cs or IService1.vb file and delete the code within the namespace declaration leaving the namespace declaration. Inside the namespace declaration define a new interface called ICalculator as shown in the code below.

 打开 IService1.cs 文件，删除命名空间内的代码，保留命名空间的声明。在命名空间中定义一个新的接口，接口名称为ICalculator ，接口的代码如下

This contract defines an online calculator. Notice the ICalculator interface is marked with the ServiceContractAttribute attribute. This attribute defines a namespace that is used to disambiguate the contract name. Each calculator operation is marked with the OperationContractAttribute attribute.

Note:

When using attributes to annotate an interface, member, or class, you can drop the "Attribute" part from the attribute name. So ServiceContractAttribute becomes [ServiceContract] in C#, or<ServiceContract> in Visual Basic.