如何比较HMAccessory的实例

Question

由于iOS9的identifier属性HMAccessory已被折旧。是否有另一种方法来比较两个不同的HMAccessory实例？

Answer 1

新办法确定的iOS 9 HMAccessory是使用

@available(iOS 9.0, *) 
@NSCopying public var uniqueIdentifier: NSUUID { get } 

Answer 2

好吧想出了一个解决方案。有一个HMCharaceteristicHMCharaceteristicTypeSerialNumber。做一个扩展HMAccessory：

extension HMAccessory { 
var serialNumber: String? { 
    get { 
    for service in services { 
    for characteristic in service.characteristics { 
    if characteristic.characteristicType == HMCharacteristicTypeSerialNumber { 
     return characteristic.value as? String 
    } 
    } 
    } 
    return nil 
    } 
} 
} 

现在可以比较：

accessory1.serialNumber == accessory2.serialNumber 

任何其他解决办法？

Answer 3

有几种方法可以做到这一点。作为@Maria提到，从iOS9起，你有NSUUID财产“唯一标识符”：

@property(readonly, copy, nonatomic) NSUUID *uniqueIdentifier NS_AVAILABLE_IOS(9_0); 

此外，您还可以利用SERIALNUMBER characteristicType比较HMAccessories，但是，请记住：你应该检查配件'可达性“和”阻塞“状态。如果附件不可用或被阻塞，则可能无法读取序列号。

最后，我已经包括在目标C的实用程序代码片段（希望斯威夫特只问，或者更好，用它作为一个练习;？））：

/** @discussion：返回空字符串，如果附件无法访问。 无法提取可达状态的实际序列号。* */

[请举出如果粘贴此]

+ (NSString *)getSerialNumberFromHMAccessory:(HMAccessory *)accessory { 
    if (!accessory || !accessory.reachable || accessory.isBlocked) { 
     return @""; 
    } 

    for (HMService *service in accessory.services) { 
     NSPredicate *predicate = [NSPredicate predicateWithFormat:@"%K like %@", @"characteristicType", HMCharacteristicTypeSerialNumber]; 
     NSArray *result = [service.characteristics filteredArrayUsingPredicate:predicate]; 

     if (result && [result count] > 0 && [result[0] isKindOfClass:[HMCharacteristic class]]) { 
      HMCharacteristic *serialNumChar = (HMCharacteristic *)result[0]; 
      NSString *serialNum = [serialNumChar valueForKey:@"value"]; 
      if (serialNum && [serialNum length] > 0) { 
       //DDLogInfo(@"Found serial number: %@ for accessory named \"%@\"", serialNum, accessory.name); 
       return serialNum; 
      } 
     } 
    } 

    return @""; 
}