ios - Realm - 无法更新值 2 次

Question

我尝试更新值两次，但出现运行时错误。我的代码如下

我的模型是

class Achievement: Object {

   dynamic var name:String = ""
   dynamic var counter:Int = 0
   dynamic var happened:Bool = false

   convenience init(name:String, counter:Int, happened:Bool) {
    self.init()
    self.name = name
    self.counter = counter
    self.happened = happened
   }

   override class func primaryKey() -> String {
    return "name"
   }
}

函数是

func checkHelperNerdAch() {

    var helperNerd = Achievement()

    let realm = try! Realm()

    var results = realm.objects(Achievement).filter("name = 'helperHelperNerd'")

    for element in results {

        helperNerd = Achievement(name: element.name, counter: element.counter, happened: element.happened)

    }

    helperNerd.counter++

    try! realm.write {
        realm.add(helperNerd, update: true)
    }



   if helperNerd.counter == 8 {

        let realm = try! Realm()
        print("entering if 8")
        helperNerd.happened = false
        try! realm.write {
            realm.add(helperNerd, update: true)
        }
        print("updated inside if 8")

   }

}

应用在打印 entering if 8 后崩溃

错误是

2015-12-30 15:09:00.307 AppName[3215:640021] * Terminating app due to uncaught exception 'RLMException', reason: 'Attempting to modify object outside of a write transaction - call beginWriteTransaction on an RLMRealm instance first.' * First throw call stack: (0x2516c10b 0x24912e17 0xf6bf0b 0x1586c8 0x6cb5c 0x6cd38 0x29556043 0x29545ac3 0x26450c7f 0x26450f71 0x2512f68f 0x2512f27d 0x2512d5eb 0x25080bf9 0x250809e5 0x262ccac9 0x29310ba1 0x6db90 0x24d2f873) libc++abi.dylib: terminating with uncaught exception of type NSException

我做错了什么？

Answer 1

在第一个 write block 之后，您的 helperNerd 对象被添加到 Realm ，因此它不再是一个独立的对象。

存储对象的任何更新都应该在事务内部发生，但是您在 write block 之外分配 helperNerd.happened = false，因此会发生异常。

所以只需重写 if block 如下:

if helperNerd.counter == 8 {
    let realm = try! Realm()
    print("entering if 8")
    try! realm.write {
        helperNerd.happened = false
        // note that add() is not needed anymore
        // because we're sure object exists in realm
    }
    print("updated inside if 8")
}