获取设备电池电量及状态

1.获取当前设备的电量

[UIDevice currentDevice].batteryMonitoringEnabled = YES;

float batteryLevel = [UIDevice currentDevice].batteryLevel;

if (batteryLevel < 0.0) {

// -1.0 means battery state is UIDeviceBatteryStateUnknown

self.levelLabel.text = @“Unknown”；

}

else {

static NSNumberFormatter *numberFormatter = nil;

if (numberFormatter == nil) {

numberFormatter = [[NSNumberFormatter alloc] init];

[numberFormatter setNumberStyle:NSNumberFormatterPercentStyle];

[numberFormatter setMaximumFractionDigits:1];

}

NSNumber *levelObj = [NSNumber numberWithFloat:batteryLevel];

self.levelLabel.text = [numberFormatter stringFromNumber:levelObj];

}

2.获取设备的电池状态

NSArray *state = @[@"未知",@"不插电的",@"充电的",@"充满电的"];

UIDeviceBatteryState currentState = [UIDevice currentDevice].batteryState;

for (int i  = 0; i < [state count]; i++) {
if (i+UIDeviceBatteryStateUnknown== currentState) {
self.statelLabel.text = state[i];
}else{
self.stateLabel.text = nil;
}
}

3.注册通知中心，观察设备电量变化

[[NSNotificationCenter defaultCenter] addObserver:self

selector:@selector(batteryLevelChanged:)

name:UIDeviceBatteryLevelDidChangeNotification object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self

selector:@selector(batteryStateChanged:)

name:UIDeviceBatteryStateDidChangeNotification object:nil];