关于NSUserDefaults保存自定义变量的方式

 今天遇到一个问题，自定义了一个实例，用NSUserDefaults存储的时候，存储不了。网上搜了一下，发现需要实现两个方法，如下：

如下内容转载自：http://www.cnblogs.com/edwardlauxh/archive/2012/03/22/2411064.html

由于NSUserDefaults 不支持保存自定类,保存的对象需要实现NSCoding协议,不过自定的类型就算实现了NSCoding也不可以保存,可以通过以下方法实现:

//h文件
#import <Foundation/Foundation.h>

@interface UserBean : NSObject<NSCoding>

@property NSInteger userid;
@property(nonatomic,copy)NSString *address;
@property(nonatomic,copy)NSString *levelName;
@property(nonatomic,copy)NSString *mobile;   
@property(nonatomic,copy)NSString *telphone;   
@property(nonatomic,copy)NSString *userName;  
@property(nonatomic,copy)NSString *realName; 
@property(nonatomic,copy)NSString *email;
@property NSInteger sex;
@property(nonatomic,copy)NSString *password;
@end

//m文件

#import "UserBean.h"

@implementation UserBean
@synthesize userid,mobile,email,sex,address,password,realName,telphone,userName,levelName;

- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeObject:email forKey:@"email"];
    [aCoder encodeObject:userName forKey:@"userName"];
    [aCoder encodeObject:mobile forKey:@"mobile"];
    [aCoder encodeObject:address forKey:@"address"];
    [aCoder encodeObject:password forKey:@"password"];
    [aCoder encodeObject:realName forKey:@"realName"];
    [aCoder encodeObject:telphone forKey:@"telphone"];
    [aCoder encodeObject:levelName forKey:@"levelName"];
    [aCoder encodeInteger:sex forKey:@"sex"];
    [aCoder encodeInteger:userid forKey:@"userid"];
    
}
- (id)initWithCoder:(NSCoder *)aDecoder{
     email= [aDecoder decodeObjectForKey:@"email"] ;
    sex= [aDecoder decodeIntegerForKey:@"sex"];
    userid= [aDecoder decodeIntegerForKey:@"userid"];
    mobile= [aDecoder decodeObjectForKey:@"mobile"];
    address= [aDecoder decodeObjectForKey:@"address"];
    password= [aDecoder decodeObjectForKey:@"password"];
    realName= [aDecoder decodeObjectForKey:@"realName"];
    telphone= [aDecoder decodeObjectForKey:@"telphone"];
    userName= [aDecoder decodeObjectForKey:@"userName"];
    levelName= [aDecoder decodeObjectForKey:@"levelName"];
    return self;
}
@end

通过实现

NSKeyedArchiver转换成NSData然后保存到NSUserDefaults中,然后取值的时候可以通过NSKeyedUnarchiver读NSData获得对应的user,代码如下:

 NSUserDefaults *nsuser= [NSUserDefaults standardUserDefaults];
    UserBean *user = [[UserBean alloc]init];
    [user setSex:0];
    [user setEmail:@"22222"];
    //将对象转化为字节流
    NSData *data = [NSKeyedArchiver archivedDataWithRootObject:user];
    
    [nsuser setObject:data forKey:@"userbean"];
    //同步
    [nsuser synchronize];
    //获取字节流
    NSData *data_1 =[nsuser objectForKey:@"userbean"];
    //解码
    UserBean *user1 = [NSKeyedUnarchiver unarchiveObjectWithData:data_1];
  
    
    NSLog(@"%@",[user1 email]);

记录仅供学习。

最后再附上一篇关于数据存储方式介绍与选择的文章，觉得不错。

http://blog.youkuaiyun.com/sbitswc/article/details/8738067