I have been playing around with the iPhone SDK recently. At first I wasn't taking advantage of anything that required version SDK version 2.2. However, I recently started using some features that were added or modified in 2.1 and 2.2.
I installed the new 2.2 SDK and changed my project settings to target SDK 2.2. However, when I hit "Build and Run" in Xcode, the simulator launches with version 2.0 selected. I can change it to 2.2 and my app works as expected, however doing that kills the debug session which would have to be reattached.
Am I missing a setting somewhere that will cause the simulator to launch with version 2.2 selected?
Thanks for any info.
Maybe I'm missing something but can't you just select "Simulator - 2.2 | Debug" in the Overview select menu then "Build and Debug"?
Control-click on the Xcode project window toolbar and choose "Customize Toolbar…". From there, drag "Active Build Configuration" and "Active SDK" into the menu. Choose "Debug" for your active build configuration and "Simulator - iPhone OS 2.2" for your SDK and try again.
Sometimes the automatic grouped setting doesn't work quite right.
I'm suffering the same problem, and none of the above answers work for me, except I manually set it every time, and sadly detach it from Xcode.
来源：https://stackoverflow.com/questions/388298/iphone-simulator-default-hardware-version