Swift3.0 - 检测API

  if #available(iOS 10 ,*){
    print("支持10")
  }else{
    print("不支持10,支持10之前的版本")
  }

if #available(iOS 10, macOS 10.12, *) {
// Use iOS 10 APIs on iOS, and use macOS 10.12 APIs on macOS
} else {
    // Fall back to earlier iOS and macOS APIs
}