1通过WebClient或者Request实现，此方法略去

2通过WCF Client调用

  a通过WebChannelFactory建Channel

  b通过Channel就可以直接调用服务端方法

3代码

WCF服务端和客户端都引用Contact库

 [ServiceContract]
    public interface IUserService : IBaseWCFService
    {
        [WebGet(UriTemplate = "userID={userID}")]
        [Description("根据UserID获取用户信息")]
        UserInfo GetUserInfo(string userID);
    }

Client调用方式

using (WebChannelFactory<IUserService> wcf = new WebChannelFactory<IUserService>(new Uri("http://ipv4.fiddler:30760/Services/UserService")))
                {  
                    var channel = wcf.CreateChannel();
                    IClientChannel clientchanel = channel as IClientChannel;                   
                    channel.GetUserInfo(new Random().Next(1, 1000).ToString());
                }

WCF请求头设置，ContentType，Accept，这个的设置很让人头痛，查询了很多资料才找到实现方式

通过OperationContextScope来实现

直接代码

 using (WebChannelFactory<IUserService> wcf = new WebChannelFactory<IUserService>(endpoint))
                {
                    var channel = wcf.CreateChannel();
                    IClientChannel clientchanel = channel as IClientChannel;
                    using (new OperationContextScope(channel as IContextChannel))
                    {
                        WebOperationContext.Current.OutgoingRequest.Headers.Add("APIKey", Guid.NewGuid().ToString());
                        WebOperationContext.Current.OutgoingRequest.ContentType = "json"; 

　　　　　　　　　WebOperationContext.Current.OutgoingRequest.Accept                      
                        channel.GetUserInfo(new Random().Next(1, 1000).ToString());
                    }                   
                }