ios - 如何存储数据以备将来在 iOS 应用程序中使用

Question

我想将从网络服务中获取的数据存储在标签中。我怎样才能做到这一点？我用过:

  NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];   

但是，它没有更新值。

Answer 1

您可以像这样在 NSUserDefaults 中保存少量数据:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSString *firstName = "Bob";
[defaults setObject:firstName forKey:@"firstName"];

[defaults synchronize];

然后像这样检索它:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *firstName = [defaults stringForKey:@"firstName"];

阅读更多关于 NSUserDefaults here 的内容

如果你不想使用 NSUserDefaults，你也可以使用像这样的属性列表:

NSArray *fruits = @[@"Apple", @"Mango", @"Pineapple", @"Plum", @"Apricot"];

NSString *filePathFruits = [documents stringByAppendingPathComponent:@"fruits.plist"];
[fruits writeToFile:filePathFruits atomically:YES];

NSDictionary *miscDictionary = @{@"anArray" : fruits, @"aNumber" : @12345, @"aBoolean" : @YES};

NSString *filePathDictionary = [documents stringByAppendingPathComponent:@"misc-dictionary.plist"];
[miscDictionary writeToFile:filePathDictionary atomically:YES];

NSArray *loadedFruits = [NSArray arrayWithContentsOfFile: filePathFruits];
NSLog(@"Fruits Array > %@", loadedFruits);

NSDictionary *loadedMiscDictionary = [NSDictionary dictionaryWithContentsOfFile: filePathDictionary];
NSLog(@"Misc Dictionary > %@", loadedMiscDictionary);

参见 this文章以获取有关在 iOS 中持久存储数据的不同方法的更多信息。