how to create an interface method with CodeDom

Question

I am using CodeDom to generate my WCF service interfaces and implementation files. I cannot find any options on CodeMemberMethod that will allow me to generate an interface method. If I use MemberAttributes.Abstract I am almost there but it includes the abstract keyword which is invalid for an interface. Does anyone know the correct syntax to generate the method?

Here is the code I have developed to generate the interface file:

private void CreateServiceContractFile(Type entity, BoElement bo, DirectoryInfo serviceOutputDir, AppParameters appPrams)
{
    CodeCompileUnit serviceFileUnit = new CodeCompileUnit();

    CodeNamespace importNameSpace = new CodeNamespace("");
    importNameSpace.Imports.Add(new CodeNamespaceImport("System"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.Collections.Generic"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.Linq"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.Runtime.Serialization"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.ServiceModel"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.ServiceModel.Web"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.Text"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("ALVIN.BusinessObjects"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("DAOObjects = ALVIN.DAO"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("ALIAS.BusinessObjects"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.Data.Entity.Validation"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.ComponentModel.DataAnnotations"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("System.Data.Objects"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("ALIAS.Common.Utility"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("ALIAS.EventMessages"));
    importNameSpace.Imports.Add(new CodeNamespaceImport("ALIAS.ServiceCommon"));


    importNameSpace.Imports.Add(new CodeNamespaceImport(appPrams.BoNameSpace));

    serviceFileUnit.Namespaces.Add(importNameSpace);

    string serviceName = string.Format("{0}Service", entity.Name);

    CodeTypeDeclaration serviceClass = new CodeTypeDeclaration(serviceName);
    serviceClass.IsClass = true;
    serviceClass.BaseTypes.Add(new CodeTypeReference("I" + serviceName));
    serviceClass.TypeAttributes = TypeAttributes.Public;
    serviceClass.Comments.AddRange(Helper.CreateComment("The Service Contract class"));

    CodeParameterDeclarationExpression headerParm = new CodeParameterDeclarationExpression(
        typeof(ALIASTransactionHeader), "header");

    CodeParameterDeclarationExpression requestParm = new CodeParameterDeclarationExpression(
        bo.BoName, "requestBO");

    CodeMemberMethod enterMethod = new CodeMemberMethod();

    MethodCommentInfo methodComments = new MethodCommentInfo();
    methodComments.CommentSummaryLines.Add(string.Format("Enters a {0} into the system.", bo.BoName));
    methodComments.CommentParameters.Add(new ParameterInfo("header", "Security and Logging information for the web method"));
    methodComments.CommentParameters.Add(new ParameterInfo("requestBO", string.Format("{0} to be entered into the system", bo.BoName)));

    enterMethod.Comments.AddRange(Helper.CreateMethodComment(methodComments));
    enterMethod.Parameters.Add(headerParm);
    enterMethod.Parameters.Add(requestParm);
    enterMethod.PrivateImplementationType = new CodeTypeReference("I" + serviceName);
    //enterMethod.Attributes = MemberAttributes.Public | MemberAttributes.Abstract;
    enterMethod.Name = string.Format("Enter{0}", bo.BoName);
    

    serviceClass.Members.Add(enterMethod);

    CodeNamespace serviceNameSpace = new CodeNamespace(bo.ServiceNameSpace);

    serviceNameSpace.Types.Add(serviceClass);
    serviceFileUnit.Namespaces.Add(serviceNameSpace);

    Helper.CreateFile(serviceFileUnit, new FileInfo(serviceOutputDir + @"\" + serviceName + @".svc.cs"));
}

Answer 1

AFAIK, you do not have to specify any special attributes for an interface method. The following sample

var compUnit = new CodeCompileUnit();
var ns = new CodeNamespace("TestNamespace");
var iface = new CodeTypeDeclaration("ITest");
iface.IsInterface = true;
var mth = new CodeMemberMethod();
mth.Name = "DoSomething";
mth.ReturnType = new CodeTypeReference(typeof(string));
mth.Parameters.Add(new CodeParameterDeclarationExpression(typeof(int), "x"));
iface.Members.Add(mth);
ns.Types.Add(iface);
compUnit.Namespaces.Add(ns);
var csProv = new CSharpCodeProvider();
using (var tw = File.CreateText(@"test.cs"))
{
    var options = new CodeGeneratorOptions();
    csProv.GenerateCodeFromCompileUnit(compUnit, tw, options);
    tw.Flush();
}

Generates the following, valid output:

namespace TestNamespace {


    public interface ITest {

        string DoSomething(int x);
    }
}