Question

ridvankucuk Problem

func getHandleStatus() -> String {
    var handle = String()
    ref.queryOrderedByChild("status").observeEventType(.ChildAdded, withBlock: { snapshot in
        if let status = snapshot.value["status"] as? Int {
            if status == 0 {
                //print(snapshot.key)
                handle = snapshot.key
            } else {
                print("NO")
            }
        }
    })
    return handle
}

当我返回＆＃34; handle＆＃34;时，它总是空字符串。我设置变量＆＃34; handle = snapshot.key＆＃34;当我回来时，它仍然是空的。请帮忙。

Answer 1

首先，你的方法是异步的，它不是在等待主线程。所以写回报毫无意义。你应该做点什么。在函数之外定义变量，例如：

var handle: String? = nil {
        didSet{
            // You know handle is set now
        }
    }

并更新你的getHandleStatus方法：

func getHandleStatus(){
    var handle = String()
    ref.queryOrderedByChild("status").observeEventType(.ChildAdded, withBlock: { snapshot in
        if let status = snapshot.value["status"] as? Int {
            if status == 0 {
                //print(snapshot.key)
                self.handle = snapshot.key
            } else {
                print("NO")
            }
        }
    })
}

Firebase检索并将数据传递给变量

1 个答案: