如何在DynamicObject中处理泛型方法调用?
本文关键字:泛型方法 调用 处理 DynamicObject | 更新日期: 2023-09-27 18:04:48
我试图构建一个能够处理通用方法调用的DynamicObject
,但似乎所需的API -尽管存在于4.0框架的RC版本中-已在RTM中标记为内部(即,CSharpInvokeMemberBinder
现在是内部)。在4.0 RTM中是否有类似的代码?
public class TransparentObject<T> : DynamicObject {
private readonly T target;
public TransparentObject(T target) {
this.target = target;
}
public override bool TryInvokeMember(
InvokeMemberBinder binder, object[] args, out object result) {
var csBinder = binder as CSharpInvokeMemberBinder;
var method = typeof(T).GetMethod(binder.Name, BindingFlags.Public
| BindingFlags.NonPublic | BindingFlags.Instance);
if (method == null)
throw new MissingMemberException(string.Format(
"Method '{0}' not found for type '{1}'", binder.Name, typeof(T)));
if (csBinder.TypeArguments.Count > 0)
method = method.MakeGenericMethod(csBinder.TypeArguments.ToArray());
result = method.Invoke(target, args);
return true;
}
}
(代码取自http://bugsquash.blogspot.com/2009/05/testing-private-methods-with-c-40.html)
我知道我可以在这里使用反射来获得泛型类型参数,但我正在寻找一个更好的解决方案-如果有的话。
我能猜到的最快的等效:
private static readonly Func<InvokeMemberBinder, IList<Type>> GetTypeArguments;
static TransparentObject()
{
var type = typeof(RuntimeBinderException).Assembly.GetTypes().Where(x => x.FullName == "Microsoft.CSharp.RuntimeBinder.CSharpInvokeMemberBinder").Single();
var dynamicMethod = new DynamicMethod("@", typeof(IList<Type>), new[] { typeof(InvokeMemberBinder) }, true);
var il = dynamicMethod.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Castclass, type);
il.Emit(OpCodes.Call, type.GetProperty("Microsoft.CSharp.RuntimeBinder.ICSharpInvokeOrInvokeMemberBinder.TypeArguments", BindingFlags.Instance | BindingFlags.NonPublic).GetGetMethod(true));
il.Emit(OpCodes.Ret);
GetTypeArguments = (Func<InvokeMemberBinder, IList<Type>>)dynamicMethod.CreateDelegate(typeof(Func<InvokeMemberBinder, IList<Type>>));
}
public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
{
var method = typeof(T).GetMethod(binder.Name, BindingFlags.Public| BindingFlags.NonPublic | BindingFlags.Instance);
if (method == null) throw new MissingMemberException(string.Format("Method '{0}' not found for type '{1}'", binder.Name, typeof(T)));
var typeArguments = GetTypeArguments(binder);
if (typeArguments.Count > 0) method = method.MakeGenericMethod(typeArguments.ToArray());
result = method.Invoke(target, args);
return true;
}