无法更改匿名块中的实例变量 (Swift/Parse.com)

Question

Parse Data 是一个 PFObject class，其中包含我正在查询的 "Companies" 数据。获取数据并将其分配为 ParseData 对象工作正常，但问题是将其放入我的 listivar。从输出中可以看出，none 个 ivar 在匿名块中发生了变化。是否有解决方法或解决方案？

import Foundation
class AllCompanies: NSObject {
    var list:[ParseData] = []
    var testList:[String] = []
    var testString:String = "butter"

    override init()
    {
        super.init()
        getCompanies()
    }

    func getCompanies()
    {
        let query = ParseData.query()!
        query.findObjectsInBackgroundWithBlock { objects, error in
            if error == nil
            {
                for company in objects!
                {
                    let newCompany:ParseData = ParseData()
                    newCompany.name = company.objectForKey("Name") as! String
                    newCompany.logo = company.objectForKey("Logo") as! PFFile

                    self.list.append(newCompany)
                    self.testList.append("here")
                    self.testString = "no matter"
                }
            }
            else
            {
                print("Error: \(error) \(error?.userInfo)")
            }
        }
    }
}

方法调用：

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
Parse.setApplicationId("m0zIvk7nfP6nEUrGYzyecbhRdqTrhbUoBI00fvZ4", clientKey: "lmqPfyrkeq4p8v6cukV7aFCVdi4evb8MFyjgvnEG")
        PFAnalytics.trackAppOpenedWithLaunchOptions(launchOptions)
        let allCompanies = AllCompanies()
        print("\(allCompanies.list)")
        print("\(allCompanies.testList)")
        print("\(allCompanies.testString)")
        return true
}

Answer 1

问题是因为查询是异步的。

您应该将打印行移到查询回调闭包中。

Answer 2

getCompanies 方法是异步的？您确保运行您的 print 命令在 findObjectsInBackgroundWithBlock method.You 之前是否无法将您的异步代码编写为同步代码。试着在下面写下你的打印代码 self.testString = "no matter"。祝你好运！

无法更改匿名块中的实例变量 (Swift/Parse.com)

Cannot change instance variables in anonymous block (Swift/Parse.com)

ios

swift

parse-platform

anonymous-function

instance-variables