NSUserDefaults保存NSObject类型的方法

来源：互联网发布：淘宝网野生松杉灵芝编辑：程序博客网时间：2024/05/20 11:46

查看官方的API，NSUserDefaults支持保存的数据类型有：NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary

对于，我们创建的NSObject不可以直接保存，如果调用setObject，会提示出错，信息如下：

*** -[NSUserDefaults setObject:forKey:]: Attempt to insert non-property value ‘<Student: 0x8399f70>’ of class ‘Student’. Note that dictionaries and arrays in property lists must also contain only property values.

当保存一个Student对象时，提示我，NSUserDefaults没有这样的属性，那么如果想要保存student中的信息，可以将studnet的信息保存到一个NSDictionary中，然后获取到这个NSDictionary，再从它里面获取每一个属性；

当然这种方式弱爆了，注意一下上面保存的类型可以保存NSData类型，不防将Student类转换为NSData类型，然后

取值时再将NSData转化为Student类；

还是用代码来说明：

<span style="font-size:14px;">Student.h 代码 #import <Foundation/Foundation.h>@interface Student : NSObject <NSCoding>{    NSString *name;}@property (nonatomic, retain) NSString *name;@endStudent.ｍ 代码#import "Student.h"@implementation Student@synthesize name;- (void)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeObject:self.name forKey:@"name"];}- (id)initWithCoder:(NSCoder *)aDecoder{    self = [super init];    if (self) {        self.name = [aDecoder decodeObjectForKey:@"name"];    }    return self;}- (void)dealloc{    [name release];    name = nil;    [super dealloc];}@end调用的代码：Student *student = [[Student alloc] init];[student setName:@"Jordy"];NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];NSData *studentData = [NSKeyedArchiver archivedDataWithRootObject:student];[userDefault setObject:studentData forKey:@"Student"];[userDefault synchronize];[student release];NSData *data = [userDefault objectForKey:@"Student"];Student *stu = [NSKeyedUnarchiver unarchiveObjectWithData:data];NSLog(@"stu: %@, stu.name: %@",stu,stu.name); </span>

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