原来的老版本仍然是免费的，所以您可以使用它。我不认为有这么多的改进，随着时间的推移，将升级使这个重要的。

Possible Duplicate:
Something Better than .NET Reflector?

Possible Duplicate:
Open Source Alternatives to Reflector?

I don't consider this to be a duplicate, as the contact of the other questions is about learning how reflector works, and this question is about coping when reflector stops being free

Now that Red-Gate has said .NET Reflector will no longer be free, is there an alternative that save the pain of getting a purchase order approved?

It seems that jetbrains may be bringing out a tool:

Good news is that we’re preparing a standalone binary-as-a-source application, i.e. a decompiler + assembly browser to explore whatever .NET compiled code is legal to explore. We don’t have any specific date for release, but it’s going to be released this year, and it’s going to be free of charge. And by saying "free", we actually mean "free".

Also ilspy is a new open source tool that seems to be making good progress. ILSpy is the open-source .NET assembly browser and decompiler.

Development started after Red Gate announced that the free version of .NET Reflector would cease to exist by end of February 2011.

The old original versions are still free so you can use it. I do not think that there were so many improvements over time that would upgrading make this important.