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，实现的方法有很多。所以写了这篇总结，对于当前获取电池电量的方式进行一个整理。

方法一:通过苹果给的api获取

最简单的方式

UIDevice currentDevice].batteryMonitoringEnabled = YES;

double deviceLevel = [UIDevice currentDevice].batteryLevel;

另外一种写法

[UIDevice currentDevice].batteryMonitoringEnabled = YES;

[[NSNotificationCenter defaultCenter]addObserverForName:UIDeviceBatteryLevelDidChangeNotification object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification*notification) {

NSLog(@"电池电量：%.2f", [UIDevice currentDevice].batteryLevel);

}];

测试多次会出现偏差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

- (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;

}

方法三：找到Mac下IOKit.framework，将IOKit.framework里面的IOPowerSources.h和IOPSKeys.h拷贝到你的iOS项目中。另外, 还需要把IOKit也导入到你的工程中去，此方法也会出现偏差，不精确。

-(double)getCurrentBatteryLevel

{

//Returns a blob of Power Source information in an opaque CFTypeRef.

CFTypeRef blob = IOPSCopyPowerSourcesInfo();

//Returns a CFArray of Power Source handles, each of type CFTypeRef.

CFArrayRef sources = IOPSCopyPowerSourcesList(blob);

CFDictionaryRef pSource = NULL;

const void *psValue;

//Returns the number of values currently in an array.

int numOfSources = CFArrayGetCount(sources);

//Error in CFArrayGetCount

if (numOfSources == 0)

{

NSLog(@"Error in CFArrayGetCount");

return -1.0f;

}

//Calculating the remaining energy

for (int i = 0 ; i < numOfSources ; i++)

{

//Returns a CFDictionary with readable information about the specific power source.

pSource = IOPSGetPowerSourceDescription(blob, CFArrayGetValueAtIndex(sources, i));

if (!pSource)

{

NSLog(@"Error in IOPSGetPowerSourceDescription");

return -1.0f;

}

psValue = (CFStringRef)CFDictionaryGetValue(pSource, CFSTR(kIOPSNameKey));

int curCapacity = 0;

int maxCapacity = 0;

double percent;

psValue = CFDictionaryGetValue(pSource, CFSTR(kIOPSCurrentCapacityKey));

CFNumberGetValue((CFNumberRef)psValue, kCFNumberSInt32Type, &curCapacity);

psValue = CFDictionaryGetValue(pSource, CFSTR(kIOPSMaxCapacityKey));

CFNumberGetValue((CFNumberRef)psValue, kCFNumberSInt32Type, &maxCapacity);

percent = ((double)curCapacity/(double)maxCapacity * 100.0f);

return percent;

}

return -1.0f;

}

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。