C++ 我需要购买 Qt 框架吗？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/8368630/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Do I need to buy the Qt Framework?
提问by Landin Martens
I want to develop a C++ application that will work on ALL operating systems. This application will be free until version 1.5 (to make sure it is of high quality). I do not want this application to be open source. The public will only have access to the installer "EXE" and that is it. All source code will be kept and maintained by me, and not under a legal company (for now at least).
我想开发一个适用于所有操作系统的 C++ 应用程序。此应用程序在 1.5 版之前将免费提供（以确保其具有高品质）。我不希望这个应用程序是开源的。公众只能访问安装程序“EXE”，仅此而已。所有源代码将由我保存和维护，而不是由合法公司（至少现在）。
So with the information above do I need to buy the Qt framework or can I use the free version? I am always confused with these free license agreements like LGPL and GPL. I can read it a million times and still not know if I can use it or not.
那么根据以上信息，我需要购买 Qt 框架还是可以使用免费版本？我总是对 LGPL 和 GPL 等免费许可协议感到困惑。我可以阅读一百万次，但仍然不知道我是否可以使用它。
If I can use the Qt for free, in regular non legal terms; what must I do or how will be restricted so that I can see Qt for free.
如果我可以在常规的非法律条款中免费使用 Qt；我必须做什么或如何限制，以便我可以免费查看 Qt。
I really hope I can use the Qt for free, for when this application does cost money I still want to have a free version, with less feature and the paid version will still be very cheap. Not enough to make me rich, just enough so I don't go broke haha. We are talking like $5 for the paid version or something.
我真的希望我可以免费使用 Qt，因为当这个应用程序确实要花钱时，我仍然想要一个免费版本，功能较少，付费版本仍然非常便宜。不足以让我富有，只是足以让我不破产哈哈。我们谈论的是付费版本之类的 5 美元。
回答by Martin Beckett
You can (and we do) sell commercial apps based on the Qt libs.
您可以（而且我们确实）销售基于 Qt 库的商业应用程序。
All you need to do is.
您需要做的就是。
1, Dynamically link your exe against the Qt dll's. so your product's installer includes your app.exe and only the used Qtcore4.dll etc. This is a good idea anyway because you can upgrade your app without having to change MBs of dlls.
1，动态链接你的 exe 到 Qt dll。所以您的产品安装程序包含您的 app.exe 和仅使用过的 Qtcore4.dll 等。无论如何，这是一个好主意，因为您可以升级您的应用程序，而无需更改 MB 的 dll。
2, If you fix or change anything in Qt you need to offer the changes (to the Qt sources only) to your customers and/or back to the Qt people. This is pretty unlikely since Qt is very high quality.
2，如果您修复或更改 Qt 中的任何内容，您需要将更改（仅限 Qt 源）提供给您的客户和/或返回给 Qt 人员。这不太可能，因为 Qt 的质量非常高。
The only reason to buy a Qt license is if you need to run on a platform where dynamic linking isn't possible - perhaps a settop box - or you need extra technical support.
购买 Qt 许可证的唯一原因是，如果您需要在无法进行动态链接的平台（可能是机顶盒）上运行，或者您需要额外的技术支持。
ps. Even if you don't modify Qt you do need to provide the original Qt source if a customer asks for it. But this is just a matter of pointing them at the Qt site.
There is never any requirement to reveal your source code.
附：即使您不修改 Qt，您也确实需要在客户要求时提供原始 Qt 源代码。但这只是将它们指向 Qt 站点的问题。
从来没有任何要求透露您的源代码。
回答by Jon
It dependson how you intend to integrate Qt with your application. If you link to Qt dynamicallythen you don't need a commercial license (the LGPL will suit you).
这取决于您打算如何将 Qt 与您的应用程序集成。如果您动态链接到 Qt，那么您不需要商业许可证（LGPL 将适合您）。
If on the other hand you link to Qt statically then my understanding is that you will need a commercial license.
另一方面，如果您静态链接到 Qt，那么我的理解是您将需要商业许可证。
