并非所有 NSUserDefaults 都在应用程序重新启动时恢复 [英] Not all NSUserDefaults are restored on app relaunch

问题描述

我正在将 2 个自定义列表转换​​为 json 字符串并将其存储在 NSUserDefaults 中.像这样:-

I am converting 2 custom lists into a json string and storing it the NSUserDefaults. Something like so:-

NSUserDefaults.StandardUserDefaults.SetString(JsonConvert.SerializeObject(stationList.Take(50)), "StationList1");
NSUserDefaults.StandardUserDefaults.SetString(JsonConvert.SerializeObject(stationList.Skip(50).Take(50)), "StationList2");  

如果我像下面那样在保存它们后立即尝试检索它们，我会得到保存的值:-

If I try and retrieve them immediately after saving them like below I get the saved values:-

savedStationList1 = NSUserDefaults.StandardUserDefaults.StringForKey("StationList1");
  savedStationList2 = NSUserDefaults.StandardUserDefaults.StringForKey("StationList2");  

但问题是如果我重新启动应用程序，并尝试在代码的另一部分获取上述值，我只能获取以下值:-

But the issue is if I restart the app, and try to get the above values in another part of the code, I only get the value for:-

savedStationList2 = NSUserDefaults.StandardUserDefaults.StringForKey("StationList2");  

并且下面的值始终为 null :-

and the value for below is always null :-

 savedStationList1 = NSUserDefaults.StandardUserDefaults.StringForKey("StationList1");

我不会在应用内的任何地方覆盖这些值.有什么办法可以解决这个问题吗?

I do not override these values anywhere within the app. Is there a way I can solve this?

感谢任何帮助

推荐答案

虽然 iOS 系统本身确实存储了通过userdefaults"添加的数据，但它可能不会立即执行此操作.我建议添加以下行:

Although natively the iOS system does store data added through 'userdefaults' it may not do this instantly. I would suggest adding the following line:

NSUserDefaults.StandardUserDefaults.Synchronise();

将数据存储到标准用户默认值后，运行同步并测试您是否可以提取数据，您应该会发现现在可以正常工作了.

After you store data to standard user defaults run the synchronise and test that you can extract the data, you should find that this will now work correctly for you.

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