如何在NSUserDefaults中存储自定义对象

Question

我为重复的问题道歉。 我是ios的新手。 我想在userdefaults中存储自定义对象。 我正在使用objective-c。

提前致谢

Answer 1

首先，您创建自定义类，如下所示。

CustomObject.h

#import <Foundation/Foundation.h>

@interface CustomObject : NSObject<NSCoding>

@property(strong,nonatomic)NSString *name;

@end 

CustomObject.m

#import "CustomObject.h"

@implementation CustomObject



- (void)encodeWithCoder:(NSCoder *)encoder {
    //Encode properties, other class variables, etc
    [encoder encodeObject:self.name forKey:@"name"];

}

- (id)initWithCoder:(NSCoder *)decoder {
    if((self = [super init])) {
        //decode properties, other class vars
        self.name = [decoder decodeObjectForKey:@"name"];

    }
    return self;
}

然后创建CustomObject类对象并存储在NSUserDefaults中

像这样存储你的对象

CustomObject *object =[CustomObject new];
object.name = @"test";

NSMutableArray *arr = [[NSMutableArray alloc]init];
[arr  addObject:object];

NSData *encodedObject = [NSKeyedArchiver archivedDataWithRootObject:arr];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:encodedObject forKey:@"storeObject"];
[defaults synchronize];

从NSUserDefaults中获取自定义对象

 NSData *storedEncodedObject = [defaults objectForKey:@"storeObject"];
        NSArray *arrStoreObject = [NSKeyedUnarchiver unarchiveObjectWithData:storedEncodedObject];
        for (int i=0; i<arrStoreObject.count; i++)
        {
            CustomObject *storedObject = [arrStoreObject objectAtIndex:i];
            NSLog(@"%@",storedObject.name);

        }

Answer 2

在Swift 3中

        // set a value for key
        let encodedData = NSKeyedArchiver.archivedData(withRootObject: #YOUR OBJECT#)
        UserDefaults.standard.set(encodedData, forKey: #YOUR KEY#)

        // retrieving a value for a key
        if let data = UserDefaults.standard.data(forKey:  #YOUR KEY#),
            let obj = NSKeyedUnarchiver.unarchiveObject(with: data) as? #YOUR OBJECT# {
        } else {
            print("There is an issue")
        }