NSUserDefaults值未保存到iPhone

本文介绍了NSUserDefaults值未保存到iPhone的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

使用以下代码保存sessionID.

NSUserDefaults * sessions = [NSUserDefaults standardUserDefaults];[sessions setObject:sID forKey:@"sessionsID"]；[会话同步]；NSLog(@会话值已保存");

检索值的代码为:

NSUserDefaults * sessions = [NSUserDefaults standardUserDefaults];NSString * myString = [会话stringForKey:@"sessionsID"];NSLog(@"nsuser:％@"，myString);

但是在控制台上它显示为:

2012-01-03 15:37:37.292 LoginTest [574:12503] sID:c339af83caa5355d124f70e3f22c193d2012-01-03 15:37:37.296 LoginTest [574:12503]会话值已保存2012-01-03 15:37:37.297 LoginTest [574:12503]帐户:("uid=demo@url"，"o = Demo"，"o = Und")2012-01-03 15:37:37.302 LoginTest [574:12503] sID :(空)2012-01-03 15:37:37.304 LoginTest [574:12503]会话值已保存2012-01-03 15:37:37.304 LoginTest [574:12503]帐户:(空)2012-01-03 15:37:37.305 LoginTest [574:12503]未创建任何会话

为什么要两次调用它，一次将其保存并显示出来，第二次给出空值.

我正在使用ARC.

我对此感到困惑...请指导我如何解决此问题

解决方案

我们不知道为什么它被调用了两次；这是您的应用程序:)

在 [sessions setObject:sID forKey:@"sessionsID"];上放置一个断点；

第一次被击中 sID 将是有效的.

然后发生了使 sID :(

第二次被击中，它看起来像 sID 为 null -您应该能够使用控制台/堆栈来弄清楚为什么它被两次调用./p>

Using the below code to save the sessionID.

NSUserDefaults *sessions = [NSUserDefaults standardUserDefaults]; [sessions setObject:sID forKey:@"sessionsID"]; [sessions synchronize]; NSLog(@"Session Value Saved");

The code to retrieve the value is:

NSUserDefaults *sessions = [NSUserDefaults standardUserDefaults]; NSString *myString = [sessions stringForKey:@"sessionsID"]; NSLog(@"nsuser: %@", myString);

But on console it is showing like:

2012-01-03 15:37:37.292 LoginTest[574:12503] sID: c339af83caa5355d124f70e3f22c193d 2012-01-03 15:37:37.296 LoginTest[574:12503] Session Value Saved 2012-01-03 15:37:37.297 LoginTest[574:12503] Accounts: ("uid=demo@url", "o=Demo","o=Und") 2012-01-03 15:37:37.302 LoginTest[574:12503] sID: (null) 2012-01-03 15:37:37.304 LoginTest[574:12503] Session Value Saved 2012-01-03 15:37:37.304 LoginTest[574:12503] Accounts: (null) 2012-01-03 15:37:37.305 LoginTest[574:12503] No Session created

why is it being called two times and once it saves the values and shows them up and second time giving null.

I am using ARC.

I am messed-up with this... please guide me how can I resolve this issue

解决方案

We dont know why it's getting called twice; it's your app :)

Put a breakpoint on [sessions setObject:sID forKey:@"sessionsID"];

The first time this gets hit sID will be valid.

Then something is happening that is invalidating sID :(

The second time it gets hit it looks like sID is null - you should be able to use the console / stack to work out why it's being called twice.