使用反射与COM互操作 [英] Using Reflection with COM Interop

问题描述

在互操作调用之后，我回到一个COM对象。
我知道这个对象将是三个可能的COM类之一（Class1，Class2，Class3），但不知道在运行时是哪一个。

After an interop call, I get back a COM object. I know this object will be one of three possible COM classes (Class1, Class2, Class3), but do not know which one in runtime.

对象（interopObject.GetType（））返回System .__ ComObject的基本RCW包装器。

The reflection upon that object (interopObject.GetType()) returns the base RCW wrapper of System.__ComObject.

我需要的是在对象上设置一些属性 - Text1，Text2 ，... Text30（actual names，btw :)），它存在于所有三个类中。

What I need is to set some properties on the object - Text1, Text2, ... Text30 (actual names, btw :)), which exist in all three classes.

所以，问题是，我能以某种方式获得运行时类型对象（这将解决我的问题，但可能是不可能的，因为.net运行时可能没有这个信息），或者我可以设置一个COM对象的属性盲目

So, the question is, can I somehow get the runtime type of the object (this would solve my problem, but might be impossible, as the .net runtime might not have that info), or can I set a property of a COM object blindly

这是我当前的代码，它失败：

this is my current code, which fails:

for ( int i = 1; i <= 30; i++ )
{
  ProprertyInfo pi =interopObject.GetType().GetProperty("Text" +i.ToString()) 
  // this returns null for pi
  pi.GetSetMethod().Invoke(interopObject, new object[] { someValue });
}

---

三个在我永久的g头集合：

---

Thanks to Marc, these three go in my permanent gimmicks collection:

private static object LateGetValue(object obj, string propertyName)
{
  return RuntimeHelpers.GetObjectValue(NewLateBinding.LateGet(obj, null,
            propertyName, new object[0], null, null, null));
}

private static void LateSetValue(object obj, string propertyName, object value)
{
  NewLateBinding.LateSet(obj, null, propertyName, new []{value}, null, null);
}

private static void LateCallMethod(object obj, string methodName)
{
  NewLateBinding.LateCall(obj, null, methodName, new object[0], null,
            null, null, true);
}

推荐答案

在这之前，我想知道VB.Net是否会更好， Option Strict Off 允许后期绑定对象。

Until then, I wonder if VB.Net would be better, with Option Strict Off to allow late binding against object.

最差的情况：在VB.Net中写，然后使用反射器为你编写C＃;-p

Worst case: write it in VB.Net, then use reflector to write the C# for you ;-p

这里有一个例子， .VisualBasic.dll，但在C＃中很好：

Here's an example, that requires a reference to Microsoft.VisualBasic.dll, but is fine in C#:

public static object GetValue(object obj, string propertyName)
{
    return RuntimeHelpers.GetObjectValue(NewLateBinding.LateGet(obj, null,
         propertyName, new object[0], null, null, null));
}

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