最近由于项目需要，要求获取iOS手机电池电量的详细值以及变化量等信息。所以做了相关的技术调研，调研到的方法有很多。各种网站给的代码和方法，有的东拼西凑，导致我走了很多弯路，所以写了这篇总结以供有相同需求的同学共同学习，并提高效率，如有不正确的地方，请多多指教。
方法一：通过苹果官方文档里面UIDevice public API来获取，代码如下：
[UIDevicecurrentDevice].batteryMonitoringEnabled =YES; [[NSNotificationCenterdefaultCenter]addObserverForName:UIDeviceBatteryLevelDidChangeNotificationobject:nilqueue:[NSOperationQueuemainQueue] usingBlock:^(NSNotification*notification) {// Level has changed
NSLog(@"Battery Level Change");
NSLog(@"电池电量：%.2f", [UIDevicecurrentDevice].batteryLevel);
}];
// @property(nonatomic,readonly)float batteryLevel NS_AVAILABLE_IOS(3_0);
// 0 .. 1.0. -1.0 if UIDeviceBatteryStateUnknown它返回的是0.00-1.00之间的浮点值。
但是经过测试发现，在iOS7 上 它是以0.05为单位的，但是在iOS9下测试，它是以0.01为单位的，虽然也是0.01为单位，但是测试多次也会出现偏差1%左右。也就是说, 这个办法是存在缺陷的, 最起码, 它不精确。
方法二：通过runtime 获取StatusBar上电池电量控件类私有变量的值，此方法可精准获取iOS6以上电池电量
MRC:
- (int)getCurrentBatteryLevel{
if ([UIApplication sharedApplication].applicationState == UIApplicationStateActive|| [UIApplicationsharedApplication].applicationState==UIApplicationStateInactive) {
void *result = nil;
object_getInstanceVariable([UIApplication sharedApplication], "_statusBar", &result);
id status = result;
for (id aview in [status subviews]) {
for (id bview in [aview subviews]) {
int batteryLevel = 0;
if ([NSStringFromClass([bview class]) caseInsensitiveCompare:@"UIStatusBarBatteryItemView"] == NSOrderedSame&&[[[UIDevice currentDevice] systemVersion] floatValue] >= 6.0){
object_getInstanceVariable(bview, "_capacity", &result);
batteryLevel = (int)result;
NSLog(@"电池电量:%d",batteryLevel);
if (batteryLevel > 0 && batteryLevel <= 100) {
return batteryLevel;
} else {
return 0;
}
}
}
}
return 0;
}
}
ARC:
- (int)getCurrentBatteryLevel
{
UIApplication *app = [UIApplication sharedApplication];
if (app.applicationState == UIApplicationStateActive||app.applicationState==UIApplicationStateInactive) {
Ivar ivar= class_getInstanceVariable([app class],"_statusBar");
id status = object_getIvar(app, ivar);
for (id aview in [status subviews]) {
int batteryLevel = 0;
for (id bview in [aview subviews]) {
if ([NSStringFromClass([bview class]) caseInsensitiveCompare:@"UIStatusBarBatteryItemView"] == NSOrderedSame&&[[[UIDevice currentDevice] systemVersion] floatValue] >=6.0){
Ivar ivar= class_getInstanceVariable([bview class],"_capacity");
if(ivar){
batteryLevel = ((int (*)(id, Ivar))object_getIvar)(bview, ivar);
//这种方式也可以
/*ptrdiff_t offset = ivar_getOffset(ivar);
unsigned char *stuffBytes = (unsigned char *)(__bridge void *)bview;
batteryLevel = * ((int *)(stuffBytes + offset));*/
NSLog(@"电池电量:%d",batteryLevel);
if (batteryLevel > 0 && batteryLevel <= 100) {
return batteryLevel;
} else {
return 0;
}
}
}
}
}
}
return 0;
}
这个方法和上面的方法都只能获取到电池电量所占百分比，不能获取到实际的电池电量毫安时。
于是，我选择去外国网站Stack Overflow去找寻我想要的答案。从而有了以下两种能满足需求的方法。链接在这里：http://stackoverflow.com/questions/12346230/how-to-obtain-extensive-battery-info-in-ios
方法三：UIDeviceListener
这个代码类可以监控电池电量的变化，从而捕获到系统电量资源相关类的调用字典解析到相关的值。其代码设计是通过监控UIDevice currentDevice 的 BatteryState 和 BatteryLevel的值变化来用c＋＋集合来截取系统iOClass调用CoreFoudation的API从而产生部分信息的变化，最终转化成字典对象得以解析。不涉及私有API调用。github地址：https://github.com/eldade/UIDeviceListener。
然而，经过我的测试调用，这个方法的遗憾之处就是，无法获取到iOS 10易以后的相关数据。
调试iOS10系统机器之前获得到的字典的数据结构如下：
{
AdapterDetails = {
Amperage = 1000;
Description = "usb host";
FamilyCode = "-536854528";
PMUConfiguration = 1000;
Watts = 5;
};
AdapterInfo = 16384;
Amperage = 1000;
AppleRawCurrentCapacity = 1279;
AppleRawMaxCapacity = 1275;
AtCriticalLevel = 0;
AtWarnLevel = 0;
BatteryData = {
BatterySerialNumber = REDACTED;
ChemID = 355;
CycleCount = 524;
DesignCapacity = 1420;
Flags = 640;
FullAvailableCapacity = 1325;
ManufactureDate = REDACTED;
MaxCapacity = 1273;
MfgData = REDACTED;
QmaxCell0 = 1350;
StateOfCharge = 100;
Voltage = 4194;
};
BatteryInstalled = 1;
BatteryKey = "0003-default";
BootBBCapacity = 52;
BootCapacityEstimate = 2;
BootVoltage = 3518;
CFBundleIdentifier = "com.apple.driver.AppleD1815PMU";
ChargerConfiguration = 990;
CurrentCapacity = 1275;
CycleCount = 524;
DesignCapacity = 1420;
ExternalChargeCapable = 1;
ExternalConnected = 1;
FullyCharged = 1;
IOClass = AppleD1815PMUPowerSource;
IOFunctionParent64000000 = <>;
IOGeneralInterest = "IOCommand is not serializable";
IOInterruptControllers = (
IOInterruptController34000000,
IOInterruptController34000000,
IOInterruptController34000000,
IOInterruptController34000000
);
IOInterruptSpecifiers = (
<03000000>,
<26000000>,
<04000000>,
<24000000>
);
IOMatchCategory = AppleD1815PMUPowerSource;
IOPowerManagement = {
CurrentPowerState = 2;
DevicePowerState = 2;
MaxPowerState = 2;
};
IOProbeScore = 0;
IOProviderClass = AppleD1815PMU;
InstantAmperage = 0;
IsCharging = 0;
Location = 0;
Manufacturer = A;
MaxCapacity = 1275;
Model = "0003-A";
Serial = REDACTED;
Temperature = 2590;
TimeRemaining = 0;
UpdateTime = 1461830702;
Voltage = 4182;
"battery-data" = {
"0003-default" = <...>;
"0004-default" = <...>;
"0005-default" = <...};
"built-in" = 1;
}
方法四：EEIOKitListener
github地址：https://github.com/eldade/EEIOKitListener这个就可以实现iOS 8、9、10的电池信息获取，不过iOS10下获取数据比较少。这个方法的原理是通过私有API来获取IOKit.Framework中系统电池电量的相关类IOClass的属性AppleARMPMUCharger获取如下的结构。{
AdapterInfo = 16384;
AtCriticalLevel = 0;
CurrentCapacity = 1472;
ExternalChargeCapable = 1;
ExternalConnected = 1;
FullyCharged = 0;
IOClass = AppleARMPMUCharger;
IsCharging = 1;
MaxCapacity = 1600;
Voltage = 4281;
}
经过观察数据变化发现，这个类中发出的消息通知，是根据电池的电量的变化以及电压变化而产生的。然后这个电池电量值的变化的幅度也是总电容量的百分之一。
所以，综上所述，从iOS 10 之后苹果再次增加了系统部分的安全性的管理，我们也无法通过各种黑科技获取到更加详细的信息。而且，即使获取到了上述的数值，也不能达到更精准的值。当然，可能有更好的，更强大的方法，获取到更精准的值，只是我暂时没有找到，如果你有更好的方案，望不吝赐教。
