无法设置NSUserDefaults字段 [英] Cannot set NSUserDefaults field

问题描述

我在我的应用初始化（第一次）中有以下代码：

I have the following code in my initialization (first time) of my app:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=@"1";
[defaults setObject:uid forKey:@"init_val"];
[defaults synchronize];

很久以后在代码中（响应按下按钮）我使用以下方法检查值：

Much later in the code (in response to a button press) I check the value using:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *initVal=[defaults objectForKey:@"init_val"];

initVal始终为零。我已经检查过，init_val在我的设置包中的设置与我可以设置和读取的其他字段完全相同（没有问题）（它们都设置了一个名为Key的字段。

initVal is always nil. I have checked and init_val is set up exactly the same in my settings bundle as another field that I can set and read from without issue (they are both set up with a single field named "Key".

推荐答案

@ mlewis54：

@mlewis54:

你可以试试这段代码。我很确定它会起作用你。

You can try this code. I am very sure that it will work for you.

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=@"1";
[defaults setObject:uid forKey:@"init_val"];
[defaults synchronize];

对于检索数据，您应使用以下代码：

NSString *initVal=[[NSUserDefaults standardUserDefaults] valueForKey:@"init_val"];

OR

NSString *initVal=[[NSUserDefaults standardUserDefaults] objectForKey:@"init_val"];

编辑：

如果仍然提供 nil ，然后你可以使用以下代码：

If still it gives nil, then you can use the following code:

NSString *initVal=[NSString stringWithFormat:@"%@",[[NSUserDefaults standardUserDefaults] valueForKey:@"init_val"]];

OR

NSString *initVal=[NSString stringWithFormat:@"%@",[[NSUserDefaults standardUserDefaults] objectForKey:@"init_val"]];

希望这可以帮到你。

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