无文件动态承载WCF服务

For hosting WCF Services in IIS you usually need a .svc file. This File exposes your Service.
With ASP.NET virtual Paths you have the opportunity to load your service without a .svc file.
You can put the WCF Service inside a DLL without adding a reference to the ASP.NET WebApp.

Implementation:

- Create a Class derived from VirtualPathProvider and override the MethodsGetFile and FileExists.

- Create a Class derived from VirtualFile and override the Method Open.

- Create a Class derived from ServiceHostFactory and override the MethodCreateServiceHost.

- The VirtualPathProvider manages the calling URLs and returns a VirtualFile, if the client calls a WCF Service.

- The VirtualFile generates the .svc Content.

- The ServiceHostFactory hosts the WCF Service.

- Register the VirtualPathProvider in global.asax

Here is the code: (VirtualPathProvider)

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public class ServicePathProvider : VirtualPathProvider {     public override VirtualFile GetFile(string virtualPath)     {         if (!this.IsServiceCall(virtualPath))             return this.Previous.GetFile(virtualPath);         return new ServiceFile(virtualPath);     }       private bool IsServiceCall(string virtualPath)     {         // Check if it is a wcf service call         virtualPath = VirtualPathUtility.ToAppRelative(virtualPath);         return (virtualPath.ToLower().StartsWith("~/srv_"));     }       public override bool FileExists(string virtualPath)     {         if (!this.IsServiceCall(virtualPath))             return this.Previous.FileExists(virtualPath);         return true;     } }

VirtualFile

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public class ServiceFile : VirtualFile {     public ServiceFile(string virtualPath)         : base(virtualPath)     { }       public string GetCallingServiceName     {         get         {             // Return class name. srv_hello.svc => hello             return base.VirtualPath.Replace("/srv_", string.Empty)                         .Replace(".svc", string.Empty).ToLower();         }     }       public string GetService()     {           string srv = this.GetCallingServiceName;         // hello => Hello         return srv[0].ToString().ToUpper() + srv.Substring(1);     }       public override Stream Open()     {         var serviceDef = new MemoryStream();         var defWriter = new StreamWriter(serviceDef);           // Write host definition         defWriter.Write("<%@ ServiceHost Language=\"C#\" Debug=\"true\" Service=\"Services."+ this.GetService() + "\"  " +                         "Factory=\"DynamicServices.DynamicHostFactory, DynamicServices\" %>");         defWriter.Flush();           serviceDef.Position = 0;         return serviceDef;     } }

ServiceHostFactory

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public class DynamicHostFactory : ServiceHostFactory {     public DynamicHostFactory() { }       public override ServiceHostBase CreateServiceHost(string constructorString, Uri[] baseAddresses)     {         // Load bin/services.dll         var asm = Assembly.Load("Services");         var serviceType = asm.GetType(constructorString);         var host = new ServiceHost(serviceType, baseAddresses);           // Add endpoints. (In this example only IHello interface)         foreach (Type contract in serviceType.GetInterfaces())         {             var attribute = (ServiceContractAttribute)                 Attribute.GetCustomAttribute(contract, typeof(ServiceContractAttribute));             if (attribute != null)                 host.AddServiceEndpoint(contract, new BasicHttpBinding(), "");         }         // Add metdata behavior for generating wsdl         var metadata = new ServiceMetadataBehavior();         metadata.HttpGetEnabled = true;         host.Description.Behaviors.Add(metadata);           return host;     } }

Global.asax

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void Application_Start(object sender, EventArgs e) {     HostingEnvironment.RegisterVirtualPathProvider(new ServicePathProvider()); }

Example:
I created a DLL (Services.dll) with a WCF service. Here the Code:

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[ServiceContract] public interface IHello {     [OperationContract]     string SayHello(string name); }   public class Hello : IHello {     public string SayHello(string name)     {         return "Hello " + name;     } }

I compiled the DLL and copied it into the bin Folder of the ASP.NET Application.
When I start the WebApp and call the URL “http://localhost:{Port}/srv_hello.svc” the Service UI of the Hello Service (Services.dll) will be generated. Voila! 

EDIT:
Since WCF 4.0 there is another way to achieve the same thing. It is called “file less activation”. 
Example:

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<system.servicemodel>     <servicehostingenvironment>       <serviceactivations>         <add relativeaddress="/Hello" service="“svc_Hello.svc"/">       </add></serviceactivations>     </servicehostingenvironment>   </system.servicemodel>