虽然我玩的C＃4.0的动态，我发现了奇怪的事情发生与code是这样的：

While I playing with the C# 4.0 dynamic, I found strange things happening with the code like this:

using System.Dynamic;

sealed class Foo : DynamicObject
{
    public override bool TryInvoke(
        InvokeBinder binder, object[] args, out object result)
    {
        result = new object();
        return true;
    }

    static void Main()
    {
        dynamic foo = new Foo();

        var t1 = foo(0);
        var t2 = foo(0);
        var t3 = foo(0);
        var t4 = foo(0);
        var t5 = foo(0);
    }
}

好了，它的工作原理，但...看看的IntelliTrace窗口：

Ok, it works but... take a look at IntelliTrace window:

所以每invokation（和其他业务也对动态物体）会导致抛出和捕获异常诡异两次！

So every invokation (and other operations too on dynamic object) causes throwing and catching strange exceptions twice!

我明白，也可以使用，有时异常机制的优化，对于动态例如第一​​呼叫可被执行以一些存根代表，即简单地抛出异常 - 这可以是类似的信号，以动态的粘合剂来解决一个正确构件和再点代表。接下来调用相同的委托将没有任何执行的检查。

I understand, that sometimes exceptions mechanism may be used for optimizations, for example first call to dynamic may be performed to some stub delegate, that simply throws exception - this may be like a signal to dynamic binder to resolve an correct member and re-point delegate. Next call to the same delegate will be performed without any checks.

但是...的code以上的行为看起来很奇怪。也许抛出和捕获异常每秒两次任何操作DynamicObject - 是一个错误

But... behavior of the code above looks very strange. Maybe throwing and catching exceptions twice per any operation on DynamicObject - is a bug?

推荐答案

谢谢，我已经开了一个错误，我们正在寻找它。我会更新这个曾经我从编译器团队听到。它扔在C＃运行时绑定（Microsoft.CSharp.dll）。

Thanks, I've opened a bug, we're looking at it. I'll update this once I hear from the Compiler team. It's throwing in the C# runtime binder (Microsoft.CSharp.dll).

如果您启用了第一次机会异常的Debug.Exceptions，你会打这个。的IntelliTrace无关的错误，它只是显示你的第一次机会异常被抛出和吞咽。

If you enable first-chance exceptions in Debug.Exceptions, you will hit this. IntelliTrace has nothing to do with the bug, it's just showing you the first-chance exception being thrown and swallowed.