Question

我正在尝试使用CoreBluetooth框架，并且我已经创建了一个帮助程序类（btHelper），以使代码更易于维护等。

问题在于，在这个帮助器类中，委托方法不再被调用，就像它们最初被刷成大类时一样。是的我在helper类的.h中设置了委托方法，是的，我已将对象CBCentralManager委托设置为self。我几乎完成了所有事情，就像在一堂课中一样。我认为它与主线程有关，但我对此没什么经验。

具体来说，我想要的委托方法是

-(void)centralManagerDidUpdateState:(CBCentralManager *)central

任何人都可以告诉我，为了让委托调用在这个助手类中应该工作，我必须做些什么？谢谢！

以下是PrimaryViewController类和btHelper类

btHelper.m

-(void) activateBluetooth
{
self.manager= [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}

- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
  //DELEGATE METHOD THAT NEVER GETS CALLED. SHOULD BE CALLED AS SOON AS self.manager is initiated
   self.isAvailable=FALSE;
   switch (central.state) {
    case CBCentralManagerStatePoweredOff:
        NSLog(@"CoreBluetooth BLE hardware is powered off");
        break;
    case CBCentralManagerStatePoweredOn:
        NSLog(@"CoreBluetooth BLE hardware is powered on and ready");
         self.isAvailable=TRUE;
        break;
    case CBCentralManagerStateResetting:
        NSLog(@"CoreBluetooth BLE hardware is resetting");
        break;
    case CBCentralManagerStateUnauthorized:
        NSLog(@"CoreBluetooth BLE state is unauthorized");
        break;
    case CBCentralManagerStateUnknown:
        NSLog(@"CoreBluetooth BLE state is unknown");
        break;
    case CBCentralManagerStateUnsupported:
        NSLog(@"CoreBluetooth BLE hardware is unsupported on this platform");
        break;
    default:
        break;
}

}

PrimaryViewController.m

-(IBAction)connect
{  
  btHelper *bluetoothManager= [[btHelper alloc]init];
  [bluetoothManager activateBluetooth];

}

Answer 1

你的帮助器实例是-connect方法中的局部变量。因此ARC在您可以接收委托方法之前释放它（以及CBCentralManager实例）。让你的助手成为PrimaryViewController的实例变量（或属性），这将解决你的问题。

@interface PrimaryViewController : UIViewController
{
    // BTHelper instead of btHelper, to follow naming convention
    BTHelper *_bluetoothManager;
}
@end

@implementation PrimaryViewController
    -(IBAction)connect
    {
      // FIXME: this don't check if _bluetoothManager is already instantiated
      _bluetoothManager = [[BTHelper alloc] init];
      [_bluetoothManager activateBluetooth];
    }
@end

Answer 2

确保您的btHelper.m采用CBCentralManagerDelegate协议。

@interface btHelper () <CBCentralManagerDelegate> {}

在上述情况下，您很可能没有使用该方法出现任何错误：

- (void)centralManagerDidUpdateState:(CBCentralManager *)central

因为在几个版本之前，编译器停止要求您声明任何私有方法（在.m文件的接口部分中）。

希望这有帮助。

委托没有调用不同的线程

2 个答案: