为什么需要提取此 WinRT 函数而其他的则不需要？

Question

在 https://docs.microsoft.com/en-us/windows/uwp/launch-resume/handle-app-prelaunch#detect-and-handle-prelaunch 处显示：

Note the TryEnablePrelaunch() function, above. The reason the call to CoreApplication.EnablePrelaunch() is factored out into this function is because when a method is called, the JIT (just in time compilation) will attempt to compile the entire method. If your app is running on a version of Windows 10 that doesn't support CoreApplication.EnablePrelaunch(), then the JIT will fail. By factoring the call into a method that is only called when the app determines that the platform supports CoreApplication.EnablePrelaunch(), we avoid that problem.

为什么这里有必要大惊小怪，而在 all other occasions 似乎没有必要？

Answer 1

实际上，确保 API 在设备上是否可用始终很重要。第一个文档中的注释强调了为什么您不应使用当前 OS 版本中不可用的 API 的原因。第二个文档对此进行了总结，并展示了检查 API 可用性的常用方法。

他们都在讲述 API 可用性的重要性。

Answer 2

这是 WinPhone 时代的过时指南。有必要将调用分解为单独的方法，以便捕获 MissingMethod 异常。