iPhone/iPad开发模拟器(Simulator)截屏
Command+Shift+3
Capture entire screen and save as a file
截取整个屏幕，保存png文件到桌面
Command+Control+Shift+3
Capture entire screen and copy to the clipboard
截取整个屏幕，保存到剪切板
Command+Shift+4
Capture dragged area and save as a file
截取屏幕指定区域，并保存png文件到桌面
Command+Control+Shift+4
Capture dragged area and copy to the clipboard
截取屏幕指定区域，并保存到剪切板
Command+Shift+4 then press Space bar = Selective App Screenshot, and save as a file
截取指定App屏幕，并保持png文件到桌面
Command+Control+Shift+4 then Space bar Capture = Selective App Screenshot, and copy to the clipboard
截取指定App屏幕，并保存到剪切板
Command+Control+C
仅仅截取模拟器内部App屏幕，不包括外部的iPhone/iPad界面
