You can automatically generate new interface that contains async versions of methods from original interface using T4 and use it in ChannelFactory
without changing interface on server side.
I used NRefactory to parse original and generate new C# source code and AssemblyReferences.tt to use nuget packages in T4 template:
<#@ template debug="false" hostspecific="true" language="C#" #>
<#@ include file="AssemblyReferences.tt" #>
<#@ assembly name="System.Core" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="ICSharpCode.NRefactory.CSharp" #>
<#@ output extension=".cs"#>
<#
var file = System.IO.File.ReadAllText(this.Host.ResolvePath("IUserService.cs"));
if(!file.Contains("using System.Threading.Tasks;"))
{ #>
using System.Threading.Tasks;
<# } #>
<#
CSharpParser parser = new CSharpParser();
var syntaxTree = parser.Parse(file);
foreach (var namespaceDeclaration in syntaxTree.Descendants.OfType<NamespaceDeclaration>())
{
namespaceDeclaration.Name += ".Client";
}
foreach (var methodDeclaration in syntaxTree.Descendants.OfType<MethodDeclaration>())
{
if (methodDeclaration.Name.Contains("Async"))
continue;
MethodDeclaration asyncMethod = methodDeclaration.Clone() as MethodDeclaration;
asyncMethod.Name += "Async";
if (asyncMethod.ReturnType.ToString() == "void")
asyncMethod.ReturnType = new SimpleType("Task");
else
asyncMethod.ReturnType = new SimpleType("Task", typeArguments: asyncMethod.ReturnType.Clone());
methodDeclaration.Parent.AddChild(asyncMethod, Roles.TypeMemberRole);
}
#>
<#=syntaxTree.ToString()#>
You pass your interface file name to template:
using System.Collections.Generic;
using System.ServiceModel;
namespace MyProject
{
[ServiceContract]
interface IUserService
{
[OperationContract]
List<User> GetAllUsers();
}
}
To get new one:
using System.Threading.Tasks;
using System.Collections.Generic;
using System.ServiceModel;
namespace MyProject.Client
{
[ServiceContract]
interface IUserService
{
[OperationContract]
List<User> GetAllUsers ();
[OperationContract]
Task<List<User>> GetAllUsersAsync ();
}
}
Now you can put it in factory to use channel asynchroniously:
var factory = new ChannelFactory<MyProject.Client.IUserService>("*");
var channel = factory.CreateChannel();
var users = await channel.GetAllUsersAsync();