只是补充一个警告:如果你打算使用混淆，检查一切仍然工作!混淆可能会改变类名和方法名。因此，如果你使用反射来调用某些方法和/或类(就像在插件架构中)，你的应用程序在混淆后可能会失败。另外，堆栈跟踪对于跟踪错误可能是无用的。

net反应堆

更新

Jared指出de4dot声称能够反编译它。

.NET Reactor provides complete protection for your sensitive intellectual property by converting your .NET assemblies into unmanaged processes which cannot be understood as CIL, and which no existing tool can decompile. Hackers have no access to any intelligible form of your source. Powerful and flexible, the .NET Reactor licensing features allow you to enforce your license conditions and protect your revenue stream by using hardware and software locks. The license manager can build trial or permanent licenses, in a matter of seconds. A fully documented software development kit (SDK), complete with examples, allows you to call the licensing system directly from your code, allowing you to create custom extensions to the licensing system.

坦率地说，有时我们需要混淆代码(例如，注册许可类等)。在这种情况下，您的项目不是免费的。在我看来，你应该花钱买个好东西。

Dotfuscator隐藏代码，. net Reflector在尝试反编译时显示错误。

您不能完全保护任何应用程序(托管与否)。如果像Playstation和iPad这样的系统都被破解了——厂商甚至控制着硬件——你的应用还有什么希望呢?幸运的是，你并不是真的想这么做。在我看来，你需要确保你的应用程序足够安全，这样别人就不会意外地窃取你的产品。

例如，如果使用每台机器许可证，那么它不应该只在安装到新的第二台机器上时才能工作。你需要一个好的错误消息来防止额外的支持呼叫，但不要花费额外的时间让它难以解决，也不要用它来打击用户。

另一个例子是限时审判。甚至不用担心简单的事情，比如用户是否可以回滚系统时钟。这样做的人知道他们违反了您的许可，只要用户知道他们违反了您的许可，您就做得够多了。

You need to do this much because users don't care about your license. Licenses are made-up things that nobody cares about until they need to. No one reads them, and they really shouldn't have to. Therefore the best way to tell the user where the boundaries are is if the out-of-the-box behavior for your application complies with the license. In this first case that means either failing to install or installing in trial-version mode the second time. For the latter, it might just mean checking a plain-text date in a configuration file. Either way, make sure you handle it in an elegant, helpful, and respectful manner.

So that explains what it means do just that much. But why not go any further? Why not plug every little hole you can find? The answer is in two parts. First, if someone will cross the ethical threshold of consciously breaking your license terms — even in a simple way — they'll also be willing to do something more difficult or dangerous like pull your application from a torrent site — and there is a certain amount of danger involved in running applications downloaded from untrusted sources. Making it any harder is only a minor annoyance for these users and risks causing problems with your paying customers. Keeping it simple may prevent someone from digging into your application and releasing a more comprehensive crack. Second, you have few eyes available to look for flaws; the hackers have many, and they have more practice finding them. You only need to miss one little flaw, and your app will have the same distribution on pirate sites as if you did nothing. You have to be right every time; they only have to be lucky once. So the effort required is very high, and the likelihood of any measure of success is very low.

Ultimately, if someone wants to pirate your application (as opposed to just using it), and that is their main goal, they will. There's nothing you can do to stop them. This is the nature of software; once the files that make up your product are on a user's computer they will be able to do with them as they wish. This is especially relevant in managed environments like Java or .NET, but it definitely applies to native code as well. Time is on their side, and given enough time any digital security can be broken.

Since you can't stop users from pirating your product, your best course of action is to engage this class of user in a way the uses them to your benefit. It is often possible to get them working for you rather than against you. With that in mind, no matter what your application is, it's probably worth it to keep a free version that is almost completely functional and doesn't expire. The difference between even a US$1 price tag and free is huge, if for no other reason than that the customer doesn't have to trust you with their credit card. A free edition of your product will not only effectively kill pirated distribution (why risk a pirated version when you can be legitimate for the same price?), it has the potential to dramatically expand your audience.

结果是，你可能需要提高付费版的价格，这样最终你就有10万免费用户，而不是2000个用户，每人20美元，其中500人愿意为“专业版”支付99美元。这比你花大量时间锁定你的产品赚得更多。不仅如此，你还可以通过多种重要方式吸引这些免费用户并利用这种关系。

一是支持。悲观主义者会借此机会抱怨支持10万免费用户的成本增加，但令人惊讶的事情却发生了:你的产品基本上可以自给自足。在没有资金支持成本的大型开源项目中，您经常会看到这种情况。用户会挺身而出，让它成为现实。

Free users generally have reduced support expectations to begin with, and for good reason. All you need to do is mark the free edition as only qualifying for community support and put up a user-moderated online forum for that purpose. Your support knowledge base is self-generating, and advanced users will shepherd those who need extra hand-holding on your behalf. Even more importantly, this will allow you to identify and correct bugs faster, ultimately improving the quality of your product and lowering total support costs. This wasn't possible before because your user base wasn't large enough, but when you treat the free users as customers it can work very well.

另一个是反馈。通过观察你的论坛，你可以学到重要的改进想法，否则你可能从来没有考虑过。这可以让你最终将更多免费用户转变为付费用户，并创造出更有吸引力的产品，从而吸引更多用户。

最后，你需要考虑市场营销。所有这些免费用户现在都是粉丝，而不是对手，他们会采取相应的行动。不仅如此，当你发布下一个版本时，这些用户都将通过你批准的分发渠道，而不是其他未知的机制。这意味着在你的下一个版本中，你开始与更大的、高度感兴趣和支持你的观众建立联系。

The best features to reserve for the professional edition are tools aimed at making it easy to do corporate deployment and management. A cracker won't see these as a compelling enough reason to hack it for his own use, but for a business looking to buy 300 licenses and push it out company-wide this is a must-have. Of course, the professional edition will be pirated anyway, but again: don't sweat it because you probably wouldn't be able to sell the product to those pirates no matter what you did, so it's not costing you any revenue.

While psychologically it can be hard to give away your product this much, hopefully you can understand how it really is the best way to go. Not only that, it's the only way to go in the long term. I know someone is out there thinking that they don't want to do it this way. After all, they've got by just fine selling their locked-down $20 product for years. But that's just too bad, because if you don't do it this way, eventually someone else will. And their product will be just as good as yours, or close enough they can get away with claiming that. Then all of a sudden your pricing looks outrageous, sales drop dramatically, and there's nothing else you can do. You can opt for an additional middle tier if you must, but it's unlikely to help you.

抱歉，完全保护应用程序是不可能的。

Use online update to block those unlicensed copies. Verify serial number from different modules of your application and do not use a single function call to do the verification (so that crackers cannot bypass the verification easily). Not only check serial number at startup, do the verification while saving data, do it every Friday evening, do it when user is idle ... Verify application file check sum, store your security check sum in different places. Don't go too far on these kind of tricks, make sure your application never crash/get into malfunction while verifying registration code. Build a useful app for users is much more important than make a unbreakable binary for crackers.