问题:

I have noticed in the iPhone Simulator an option in one of the menus to specify which OS to run the Simulator under. I'm wondering if something similar is possible for the device itself (of which I have only one), so I can test my app on the actual hardware under varying OS versions?

回答1:

It looks like you can load a specific version of the OS for testing (FYI, I have not tried this myself, so I do not know how long it takes, etc.). Plus, it probably wipes all the data.

iPhone Development Guide: Restoring System Software

4 . From the Software Version pop-up menu, choose the version of iPhone OS you want to place on the device.

If your one device is also your main phone, this might not be practical though.

回答2:

This is not possible since the iphone cant run multiple versions of its os. The simulator allows you to do this since it running a vm to simulate the os.