文档

此处整理出有用的苹果相关开发文档，供需要时查阅。

iOS 旧文档

统一后的 = 新的

typedef enum UIDeviceBatteryState : NSInteger {
    ...
} UIDeviceBatteryState;

-》想要知道对应的枚举值定义的int值

-》

The battery state for the device cannot be determined.

UIDeviceBatteryStateUnknown

-》没看到定义的值

-》无意间发现，换Swift语言后：

-》点击具体的某个定义，都可以看到具体常量枚举值定义：

case unknown
- The battery state for the device cannot be determined.
  - UIDevice.BatteryState.unknown - UIDevice.BatteryState | Apple Developer Documentation
  - https://developer.apple.com/documentation/uikit/uidevice/batterystate/unknown
  - case unknown = 0
case unplugged
- The device is not plugged into power; the battery is discharging.
  - UIDevice.BatteryState.unplugged - UIDevice.BatteryState | Apple Developer Documentation
  - https://developer.apple.com/documentation/uikit/uidevice/batterystate/unplugged
  - case unplugged = 1
case charging
- The device is plugged into power and the battery is less than 100% charged.
  - UIDevice.BatteryState.charging - UIDevice.BatteryState | Apple Developer Documentation
  - https://developer.apple.com/documentation/uikit/uidevice/batterystate/charging
  - case charging = 2
case full
- The device is plugged into power and the battery is 100% charged.
  - UIDevice.BatteryState.full - UIDevice.BatteryState | Apple Developer Documentation
  - https://developer.apple.com/documentation/uikit/uidevice/batterystate/full
  - case full = 3

-》总结来说：

此处是ObjC中看不到UIDeviceBatteryState的细节的枚举值的定义

而换成Swift的UIDevice.BatteryState，就可以看到具体的枚举的定义的常量的值了