正如您所说，由于Apple不允许应用访问必要的硬件，因此无法执行此操作。 （似乎有一种方法可以在 iOS 5 但仅使用私有API。）

As you say, there is no way to do this as Apple doesn't allow apps access to the necessary hardware. (There seems to have been a way to do it in iOS 5 but only using private APIs.)

根据这篇文章，一些应用程序正在做 - 是衡量网络吞吐量。虽然这与Wi-Fi信号强度完全不同，但对于您的应用来说，这可能是一个合理的解决方法，具体取决于它应该做什么。

What you can do - and what, according to this article, some apps are doing - is measure network throughput instead. While that is in no way identical with Wi-Fi signal strength, it may be a reasonable workaround for your application, depending on what it is supposed to do.

这里有一些Stack Overflow问题涉及测量网络吞吐量：

Here are some Stack Overflow questions dealing with measuring network throughput:

• 以编程方式确定互联网上的速度


• 计算连接/下载速度

• Determine the speed on internet programmatically
• Calculating Connection/Download Speed