动态生成 WCF Client Proxy 代码 —— My Svcutil

在《.NET Framework 3.0 之旅》中我们使用 ChannelFactory 来创建服务对象，或许你会觉得此方式有悖于 SOA 原则。没问题，现在我们使用另外一种方式来达到和 svcutil 同样的效果。 目标服务原型

[ServiceContract]

public interface ICalculate

{

    [OperationContract]

    double Add(double a, double b);

}



public class CalculateService : ICalculate

{

    public double Add(double a, double b)

    {

        return a + b;

    }

}

 

服务器代码

ServiceHost host = new ServiceHost(typeof(CalculateService));
host.AddServiceEndpoint(typeof(ICalculate), new BasicHttpBinding(), "http://localhost:8080/calc");

ServiceMetadataBehavior behavior = new ServiceMetadataBehavior();
behavior.HttpGetEnabled = true;
behavior.HttpGetUrl = new Uri("http://localhost:8080/calc");
host.Description.Behaviors.Add(behavior);

host.Open();

我们创建了一个 ServiceMetadataBehavior，只有这样我们才能获得 WSDL / MetaData。

动态创建客户端端代理代码

using System;
using System.Collections.Generic;
using System.Text;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.IO;
using System.Reflection;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;

Uri uri = new Uri("http://localhost:8080/calc");
MetadataExchangeClient client = new MetadataExchangeClient(uri, MetadataExchangeClientMode.HttpGet);
MetadataSet metadata = client.GetMetadata();
WsdlImporter importer = new WsdlImporter(metadata);

CodeCompileUnit ccu = new CodeCompileUnit();
CodeDomProvider provider = CodeDomProvider.CreateProvider("CSharp");
ServiceContractGenerator generator = new ServiceContractGenerator(ccu);

foreach (ContractDescription description in importer.ImportAllContracts())
{
    generator.GenerateServiceContractType(description);
}

StringWriter writer = new StringWriter();
provider.GenerateCodeFromCompileUnit(ccu, writer, null);

string code = writer.ToString();
File.WriteAllText("proxy.cs", code, Encoding.Default);

运行上述代码后，打开 proxy.cs，你看到了什么？好了，把这个文件加到客户端项目中去就 OK 了。其实利用此方式，我们还可以动态生成客户端代理程序集，实现动态调用，有关此方式，可以参考我以前写的《动态调用 WebService》。