C#使用Dynamic关键字通过字符串访问属性而不进行反射

Question

我想写类似以下内容:

//  I will pass in a number of "properties" specified as strings that I want modified
string[] properties = new [] { "AllowEdit", "AllowDelete" };

//  Casting the component I'm using to a dynamic object of some sort ?
dynamic d = myGridComponent;

//  Iterate over the strings and set the properties
foreach(var s in properties) 
{
  //d.s = true; // 
  //d[s] = true; // this format would be ideal
}

我在想,如果有一个简单的方法来做到这一点,而无需使用反射[ .GetProperty(...).GetValue(...,...)使用新的C#4.0关键字]: dynamic.

似乎可能有某种方式,......我只是不确定确切的机制,并且无法找到合适的资源来将所有部分组合在一起.

想法？

[编辑]看起来有一个名为"Clay"的包以某种方式实现了这种类型的功能. 关于主题的CodePlex Scott Hanselman的粘土

Answer 1

可以办到.你只需要重写TryGetIndex的DynamicObject.我需要类似的东西来调用类型的静态成员,但希望你能得到这个想法.请注意,这当前不适用于具有泛型类型参数的方法或过载的方法,从而限制了它的实用程序:

internal class StaticMembersDynamicWrapper : DynamicObject
{
    private readonly IDictionary<String, MemberInfo> staticMembers = new Dictionary<string, MemberInfo>();
    private readonly Type type;

    public StaticMembersDynamicWrapper(Type type)
    {
        this.type = type;
        type.GetMembers(BindingFlags.FlattenHierarchy | BindingFlags.Static | BindingFlags.Public)
            .Each(member => staticMembers[member.Name] = member);
    }

    public override bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object result)
    {
        var name = indexes[0] as string;

        MemberInfo member;

        if (false == staticMembers.TryGetValue(name, out member))
        {
            result = null;
            return false;
        }

        var prop = member as PropertyInfo;
        if (prop != null)
        {
            result = prop.GetValue(null, null);
            return true;
        }
        var method = member as MethodInfo;
        if (method != null)
        {
            var parameterTypes = (from p in method.GetParameters()
                                  select p.ParameterType).ToArray();
            var delegateType = method.ReturnType != typeof (void)
                            ? Expression.GetFuncType(parameterTypes.Union(new[]{method.ReturnType}).ToArray())
                            : Expression.GetActionType(parameterTypes);
            result = Delegate.CreateDelegate(delegateType, method);
            return true;
        }
        result = null;
        return false;
    }
}

dynamic d = new StaticMembersDynamicWrapper(typeof(string));
var result = d["IsNullOrEmpty"](String.Empty);