BLE Status
CoreBluetooth提供的Framework物件内容都是以CB开头命名，以下内容以CB代表CoreBluetooth，CB提供CBCentralManagerDelegate让我们得知目前Bluetooth的状态，从之后可以做一些互动机制提供使用者参考。
在使用CBCentralManagerDelegate之前我们要先宣告CBCentralManager，这物件用来管理在Central模式时，也提供Bluetooth状态及一些功能，这个章节可以完成读取Bluetooth的状态，并利用NSLog印出来。
ViewController.h
//-----------start-----------
@interface ViewController : UIViewController <CBCentralManagerDelegate> {
}
@property (nonatomic,strong) CBCentralManager *CM;
@property (nonatomic,strong) CBPeripheral *connectedPeripheral;
@end
//------------end------------
ViewController.m
初始化CBCentralManager，并将delegate设定为ViewController
//-----------start-----------
#import "ViewController.h"
@interface ViewController ()
{
}
@end
@implementation ViewController
@synthesize CM;
@synthesize connectedPeripheral;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
CM= [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}
//------------end------------
增加状态的Delegate 「centralManagerDidUpdateState」，Bluetooth状态有改变时都会呼叫此method，总共有六种状态。
//-----------start-----------
-(void)centralManagerDidUpdateState:(CBCentralManager*)cManager
{
NSMutableString* nsmstring=[NSMutableString stringWithString:@"UpdateState:"];
BOOL isWork=FALSE;
switch (cManager.state) {
case CBCentralManagerStateUnknown:
[nsmstring appendString:@"Unknown\n"];
break;
case CBCentralManagerStateUnsupported:
[nsmstring appendString:@"Unsupported\n"];
break;
case CBCentralManagerStateUnauthorized:
[nsmstring appendString:@"Unauthorized\n"];
break;
case CBCentralManagerStateResetting:
[nsmstring appendString:@"Resetting\n"];
break;
case CBCentralManagerStatePoweredOff:
[nsmstring appendString:@"PoweredOff\n"];
break;
case CBCentralManagerStatePoweredOn:
[nsmstring appendString:@"PoweredOn\n"];
isWork=TRUE;
break;
default:
[nsmstring appendString:@"none\n"];
break;
}
NSLog(@"%@",nsmstring);
}
//------------end------------
除了可以利用Delegate方式在状态变动时立即知道目前的状态，当然也可以在当下直接使用Method的方式取得讯息
CM.state
加上这些功能后，执行一下看看结果：
2014-01-20 14:44:50.689 BluetoothLE Status[13633:70b] UpdateState:Unsupported
如果您是iPhone4或iPad2之前的机器，那执行的结果就会是** CBCentralManagerStateUnsupported**，无法支援的状态，在您的机器有支援下，大部分都会是「CBCentralManagerStatePoweredOff/CBCentralManagerStatePoweredOn」，有开Bluetooth与未开Bluetooth。