我一直在问的一个Android应用程序我写的，这是伟大的一些复习的副本，但我不愿意放弃了完整的应用程序，只是任何人。我想打一个时间限制的版本（这工作了大约两个星期，然后咽了气）。

I've been asked for some review copies of an Android app I've written, which is great, but I'm not willing to give out the full app to just anyone. I want to make a time-limited version (which works for about two weeks, then gives up the ghost).

什么是做到这一点的最简单的方法是什么？我没有测试此我自己，但我认为，从理论上讲，如果一个使用到期两周可能工作密钥库构建的应用程序。那是正确的，还是我要放线code中，如果你尝试了一组日期后，以引导它而关闭它的应用程序？

What is the easiest way to do this? I haven't tested this myself, but I think that in theory if one built the app using a keystore which expires in two weeks might work. Is that correct, or do I have to put a line of code in the app which shuts it down if you attempt to boot it after a set date?

推荐答案

密钥库的应用程序在安装后不检查;只在安装时的时间验证。

The keystore is not checked after the application is installed; only at installation time is the date verified.

您将不得不把自己的时间限制code，我想。但如果你想成为真正的偏执狂，你可以认为用户可能会改变他们的设备的时钟。

You would have to put in your own time limit code, I imagine. Though if you want to be really paranoid, you could consider that the user could alter their device's clock.

另外，你可以做一个网上办理登机手续（与时间服务器上），或使每个APK，你伸手，有一个单独的令牌嵌入这对您的服务器得到验证。

Alternatively, you could do an online check (against time on your server), or make each APK that you hand out have an individual token embedded which gets validated against your server.