获取设备电池状态

//Get permission for Battery Monitoring
[[UIDevice currentDevice] setBatteryMonitoringEnabled:YES];
UIDevice *myDevice = [UIDevice currentDevice];

[myDevice setBatteryMonitoringEnabled:YES];
double batLeft = (float)[myDevice batteryLevel] * 100;
NSLog(@"%.f",batLeft);

int d = myDevice.batteryState;
//Returns an Integer Value 
//UIDeviceBatteryStateUnknown 0
//UIDeviceBatteryStateUnplugged 1
//UIDeviceBatteryStateCharging 2
//UIDeviceBatteryStateFull 3

//Using notifications for Battery Monitoring
-(void)startMonitoringForBatteryChanges
{
// Enable monitoring of battery status
[[UIDevice currentDevice] setBatteryMonitoringEnabled:YES];
// Request to be notified when battery charge or state changes
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkBatteryStatus) name:UIDeviceBatteryLevelDidChangeNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkBatteryStatus) name:UIDeviceBatteryStateDidChangeNotification object:nil];
}
-(void) checkBatteryStatus
{
NSLog (@"Battery Level is %.f",[[UIDevice currentDevice] batteryLevel]*100);
 int d=[[UIDevice currentDevice] batteryState];
    if (d==0)
    {
        NSLog(@"Unknown");
    }
    else if (d==1)
    {
        NSLog(@"Unplugged");
    }
    else if (d==2)
    {
        NSLog(@"Charging");
    }
    else if (d==3)
    {
        NSLog(@"Battery Full");
    }
}