I can't find iOS simulator screenshots (supposedly created using cmd+S) since updating to Xcode 4.3 (running on 10.7.3 Lion).
They aren't in ~Library/Application Support/Developer/Shared/Xcode/Screenshots.
Presumably they moved when Xcode moved from Developer, but Spotlight can't tell me where they are either.
iOS Simulator screen shots are saved to your desktop (~/Desktop). The file names are of the form iOS Simulator Screen shot Feb 28, 2012 12.16.23 PM.png.
You can also choose Edit > Copy Screen (default shortcut: ⌃⌘C) to copy the screen shot directly to your clipboard.
Press Command+S. The screen shot will be saved on your desktop.
On iOS 9.3, the screen shots are called Simulator Screen Shot <timestamp>.png and are still located in ~/Desktop.
For newcomers, let's just use Xcode "Debug" option in the Menu:
Debug -> View Debugging -> Take screenshot of yourPhoneName
(see image below)
The screenshots are saved on the Desktop. I tried only for phone connected to my computer, but it should work also on simulators.
来源：https://stackoverflow.com/questions/9487157/where-does-the-ios-simulator-save-screen-shots