调用私有方法开启关闭蓝牙

@interface MTBluetooth : NSObject

/**
 *  蓝牙是否可用
 *
 *  @return
 */
+ (BOOL)isAvaliable;

/**
 *  是否开启
 *
 *  @return <#return value description#>
 */
+ (BOOL)isPower;

/**
 *  开启蓝牙
 */
+ (void)openBluetooth;

/**
 *  关闭蓝牙
 */
+ (void)closeBluetooth;

@end

#import "MTBluetooth.h"


// private methods
int IOBluetoothPreferencesAvailable();

int IOBluetoothPreferenceGetControllerPowerState();
void IOBluetoothPreferenceSetControllerPowerState(int state);

int IOBluetoothPreferenceGetDiscoverableState();
void IOBluetoothPreferenceSetDiscoverableState(int state);

// dry
int BTSetParamState(int state, int (*getter)(), void (*setter)(int)) {
    if (state == getter()) {
        return EXIT_SUCCESS;
    } else {
        setter(state);
        
        usleep(1000000); // Just wait, checking getter even in 10 seconds gives old result
        return EXIT_SUCCESS;
    }
}

// short names
typedef int (*getterFunc)();
typedef int (*setterFunc)(int);

#define BTAvaliable IOBluetoothPreferencesAvailable

#define BTPowerState IOBluetoothPreferenceGetControllerPowerState
int BTSetPowerState(int state) {
    return BTSetParamState(state, BTPowerState, IOBluetoothPreferenceSetControllerPowerState);
}

#define BTDiscoverableState IOBluetoothPreferenceGetDiscoverableState
int BTSetDiscoverableState(int state) {
    return BTSetParamState(state, BTDiscoverableState, IOBluetoothPreferenceSetDiscoverableState);
}

@implementation MTBluetooth

+ (BOOL)isAvaliable {
    return BTAvaliable();
}

+ (BOOL)isPower {
    if ([self isAvaliable]) {
        return BTPowerState() == 1;
    }
    return NO;
}

+ (void)openBluetooth {
    BTSetPowerState(1);
}

+ (void)closeBluetooth {
    BTSetPowerState(0);
}

@end