使用 NSUserDefaults 读取和写入自定义对象

众所周知，NSUserDefaults只能保存诸如NSArray、NSDictionary、NSData、NSNumber等基本数据类型，如果我们强制保存自定义的类，就会出现这个错误：Attempt to set a non-property-list object as an NSUserDefaults value for ，解释起来：【试图将一个非属性列表对象设置为 NSUserDefaults】接下来就说说如何吧自定义的对象保存到NSUserDefaults中去。

自定义的类实现<NSCoding>协议中的- (id) initWithCoder: (NSCoder *)coder方法和- (void) encodeWithCoder: (NSCoder *)coder方法

#pragma mark NSCoding

- (id)initWithCoder:(NSCoder *)aDecoder{  // 解码

if (self == [super init]) {

alias = [aDecoder decodeObjectForKey:JSON_NAME];

mobile = [aDecoder decodeObjectForKey:JSON_MOBILE];

signtime = [[aDecoder decodeObjectForKey:JSON_TIMESTAMP] longValue];

endtime = [[aDecoder decodeObjectForKey:JSON_END_TIME] longValue];

cmobile = [aDecoder decodeObjectForKey:JSON_CMOBILE];

}

return self;

}

- (void)encodeWithCoder:(NSCoder *)aCoder{  // 编码

[aCoder encodeObject:alias forKey:JSON_NAME];

[aCoder encodeObject:mobile forKey:JSON_MOBILE];

[aCoder encodeObject:[NSNumber numberWithLong:signtime] forKey:JSON_TIMESTAMP];

[aCoder encodeObject:[NSNumber numberWithLong:endtime] forKey:JSON_END_TIME];

[aCoder encodeObject:cmobile forKey:JSON_CMOBILE];

}

保存到NSUSerDefault：

Terminal *terminal = [[Terminal alloc] init];

terminal.alias = [dict objectForKey:JSON_NAME];

terminal.mobile = [dict objectForKey:JSON_MOBILE];

terminal.signtime = [[dict objectForKey:JSON_TIMESTAMP] longValue];

terminal.endtime = [[dict objectForKey:JSON_END_TIME] longValue];

terminal.cmobile = [dict objectForKey:JSON_CMOBILE];

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:terminal];

[userDefaults setObject:data forKey:"test"];

[userDefaults synchronize];

也就是说，我们保存自定义对象时，是使用NSKeyedArchiver 把数据归档为NSData对象，然后把NSData存储到UserDefault中，NSData相当于Model

读取：

NSUserDefaults * userDefaults = [NSUserDefaults standardUserDefaults];

NSData *data =  [userDefaults objectForKey:"test"];

return [NSKeyedUnarchiver unarchiveObjectWithData:data];

读取自定义对象时，先获取到NSData，然后使用NSKeyedUnarchiver解档为自定义的对象

LOG输出，查看结果：

2014-12-10 16:31:11.815 ESO_Etws[1463:60b] alias:Q611-0334

2014-12-10 16:31:11.815 ESO_Etws[1463:60b] mobile:13841040334

2014-12-10 16:31:11.815 ESO_Etws[1463:60b] signtime:1394529151000

2014-12-10 16:31:11.816 ESO_Etws[1463:60b] endtime:1426065151000

2014-12-10 16:31:11.816 ESO_Etws[1463:60b] cmobile:

PS：

APP升级后，UserDefaults中原有的plist是不会删除的，除非用户卸载APP

清除整个UserDefaults数据的方法：

NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];

[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];  // 持久的