Objective-C：无法从NSUserDefaults设置NSMutableDictionary

Question

我试图检索保存到NSUserDefaults的NSDictionary。当我登录了什么，我试图检索，它会显示正确：

NSLog(@"%@", [[[NSUserDefaults standardUserDefaults] dictionaryForKey:@"userdetails"] mutableCopy]); 

然而，当我试图给一个变量，它返回的零。

NSMutableDictionary *test123 = [[[NSUserDefaults standardUserDefaults] dictionaryForKey:@"userdetails"] mutableCopy]; 

任何想法为什么？

Answer 1

请与我工作的代码，

保存这个样子，

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:yourMutableDictionary]; 

[[NSUserDefaults standardUserDefaults] setObject:data forKey:@"currentUser"]; 
[[NSUserDefaults standardUserDefaults]synchronize]; 

获取字典，

NSData *dictionaryData = [[NSUserDefaults standardUserDefaults] objectForKey:@"currentUser"]; 
NSDictionary *tempDict = [NSKeyedUnarchiver unarchiveObjectWithData:dictionaryData]; 

Answer 2

也许你可以尝试使用下面的代码： [[NSUserDefaults standardUserDefaults] setObject:(NSDictionary *)yourDictionary forKey:yourkey];