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我有一个包含 CLBeacon 集合的信标数组，我只想获取与 NSPredicate 中给定的 uuid、主要和次要匹配的信标。下面是对象 C 中的代码，由于谓词中的 UUID 而生成异常。如果我从查询中删除 uuidPredicate，代码可以正常工作。

 - (void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray<CLBeacon *> *)beacons inRegion:(CLBeaconRegion *)region{

        NSPredicate *uuidPredicate = [NSPredicate predicateWithFormat:@"uuid.UUIDString == [c] %@", @"03672ce6-9272-48ea-ba54-0bf679217980"];
       //NSPredicate *uuidPredicate = [NSPredicate predicateWithFormat:@"uuid == %@", @"03672ce6-9272-48ea-ba54-0bf679217980"];
        NSPredicate *majorPredicate = [NSPredicate predicateWithFormat:@"major = %ld", 1];
        NSPredicate *minorPredicate = [NSPredicate predicateWithFormat:@"minor = %ld", 3];

        NSPredicate *compoundPredicate = [NSCompoundPredicate andPredicateWithSubpredicates:@[uuidPredicate, majorPredicate, minorPredicate]];

        NSArray *pointABeacon = [beacons filteredArrayUsingPredicate:compoundPredicate];   

    }

信标阵列类似于

beacons (
    "CLBeacon (uuid:03672CE6-9272-48EA-BA54-0BF679217980, major:1, minor:1, proximity:1 +/- 0.07m, rssi:-61)",
    "CLBeacon (uuid:03672CE6-9272-48EA-BA54-0BF679217980, major:1, minor:2, proximity:1 +/- 0.07m, rssi:-62)",
    "CLBeacon (uuid:03672CE6-9272-48EA-BA54-0BF679217981, major:1, minor:3, proximity:2 +/- 1.64m, rssi:-53)"
)

例外是

*** 由于未捕获的异常“NSUnknownKeyException”而终止应用程序，原因：“[< CLBeacon 0x1c401c410 > valueForUndefinedKey:]：此类不符合键 uuid 的键值编码。”

如何过滤具有三个参数uuid，major和minor的数组？

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1 回答 1

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错误很明显：CLBeacon对象没有名为 的属性uuid。

当你打印一个CLBeacon对象时，你可能会看到“uuid”，但这不是属性的真实名称，它是proximityUUID

所以：

NSPredicate *uuidPredicate = [NSPredicate predicateWithFormat:@"uuid.UUIDString == [c] %@", @"03672ce6-9272-48ea-ba54-0bf679217980"];

应该：

NSPredicate *uuidPredicate = [NSPredicate predicateWithFormat:@"proximityUUID.UUIDString == [c] %@", @"03672ce6-9272-48ea-ba54-0bf679217980"];
于 2018-08-09T12:46:59.237 回答