我无法向发出时类型未完成的委托发出调用。我会详细说明:我已经声明了以下委托类型:
// Delegate type. The 'firstArgument' will be 'this', i.e., this is an open
// instance method: the implicit argument is here given explicitly, in
// 'firstArgument'. (See link below for explanation on open instance delegates).
public delegate Object DirectReadAccessor<T>(T firstArgument);
现在我正在尝试动态(即,使用 TypeBuilder)创建以下类:
public MyClass {
// Array of delegates. T has been replaced with MyClass because the
// argument will be 'this', which is of type MyClass.
private static DirectReadAccessor<MyClass>[] directReadAccessors;
// Method that looks up a delegate in the array of delegates and calls it
// with 'this'.
public Object DirectRead(int i) {
directReadAccessors[i](this);
}
// Method that is called by the declaring type to pass an array with the
// MethodInfo of some methods. MyClass then creates delegates for these
// methods and stores them in the directReadAccessors array.
public static void InitializeClass(MethodInfo[] directReadAccessorsMInfo) {
int length = directReadAccessorsMInfo.Length;
Type[] typeArguments = new Type[] { typeof(MyClass) };
directReadAccessors = new DirectReadAccessor<MyClass>[length];
// For each method in directReadAccessorsMInfo...
for (int i = 0; i < length; i++) {
// Create a delegate and store it in directReadAccessors.
directReadAccessors[i] = (DirectReadAccessor<MyClass>)
Delegate.CreateDelegate(
DirectReadAccessor<MyClass>, // Type of the delegate.
null, // Specify null first argument so that it's
// *open* instance.
directReadAccessorsMInfo[i].MakeGenericMethod(typeArguments) // The method.
);
}
}
}
*在打开的实例委托上。
这很棘手,因为当我尝试声明类型为 DirectReadAccessor [] 的字段 directReadAccessors 时,或者当我发出再次使用 MyClass 的方法 InitalizeClass 时,MyClass 不存在,但它还不存在(即我正在创造什么)。然而,我已经设法做到了这一切,但现在我在使用 DirectRead 方法时遇到了问题,因为一旦我将委托放在堆栈上,我不知道如何调用它。显然我需要的是以下发射:
ilGenerator.Emit(OpCodes.Callvirt, invokeMInfo);
其中 invokeMInfo 是 DirectReadAccessor 上的 Invoke 方法,我应该像这样获取它:
MethodInfo invokeMInfo = typeof(DirectReadAccessor<MyClass>).GetMethod(
"Invoke", // Name of the method.
BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, // Binding attributes.
null, // Binder.
new Type[] { typeof(MyClass) }, // Types of the arguments.
null // Modifiers for the arguments.
);
同样,问题是 MyClass 和 DirectReadAccessor 都不存在。我有 MyClass 的 TypeBuilder 和未完成的 DirectReadAccessor 类型,我是这样创建的:
directReadAccessorType = typeof(DirectReadAccessor<>).MakeGenericType(typeBuilder);
但是,如果我尝试在 directReadAccessorType 上调用 GetMethod("Invoke", ....),如上所示,我会收到 NotSupportedException,因为我无法为未完成的类型获取方法 Invoke。我已经通过在最终确定类型后进行相同的调用来测试这个假设:
typeBuilder.CreateType();
事实上,在这种情况下我没有得到例外。但是,我需要能够在最终确定类型之前获取 Invoke 方法的 MethodInfo,同时我正在为 InitializeClass 发出代码。
这是一个奇怪的情况:当我需要委托时,我会有委托,但我无法生成调用它的代码。任何人都可以提供任何帮助吗?
非常感谢,很抱歉这篇冗长的帖子。