NSUserDefaults保存或传递数据

-(void)viewDidLoad{    //NSUserDefault可以保存数据到内存中，通过-(BOOL) synchronize可以保存到IOS设备的存储器中    //创建NSUserDefaults    NSUserDefaults *userDef = [NSUserDefaults standardUserDefaults];    //保存NSString    [userDef setObject: @"test1" forKey:"tt"];     //保存UIImage    UIImage *image = [UIImage imageNamed:@"tupian.png"];    //转换为NSData对象    NSData *imageData = UIImageJPEGRepresentation(image, 1);    //UIImageJPEGRepresentation(第一个参数是UIImage对象，第二个参数是表示最大压缩比例)1表示不压缩，0表示最大压缩。    [userDef setObject:imageData forKey:@"image"];}//方法如下：-(void)setFloat:(float)forKey:(NSString *)defaultName;-(void)setBool:(BOOL)forKey:(NSString *)defaultName;-(void)setInteger:(NSInteger)forKey:(NSString *)defaultName;-(void)setObject:(id)forKey:(NSString *)defaultName;-(void)setDouble:(double)forKey:(NSString *)defaultName;-(void)setURL:(NSURL *)forKey:(NSString *)defaultName;//其中setObject中的id只支持//NSData NSString NSNumber NSArray NSDictionary;NSArray 和NSDictionary 中也只能包含这几种类型-(void)viewDidLoad{    //获取    NSUserDefaults *userDef = [NSUserDefaults standardUserDefaults];    NSString *string = [userDef stringForKey: @"tt"];    NSData *data = [userDef dataForKey:@"image"];    UIImage *image = [UIImage imageWithData:data];}//所有获取的方法如下：-(NSInteger)integerForKey:(NSString *)defaultName;-(BOOL)boolForKey:(NSString *)defaultName;-(float)floatForKey:(NSString *)defaultName;-(double)doubleForKey:(NSString *)defaultName;-(NSData *)dataForKey:(NSString *)defaultName;-(NSArray *)stringArrayForKey:(NSString *)defaultName;-(NSURL *)URLForKey:(NSString *)defaultName;-(NSString *)stringForKey:(NSString *)defaultName;-(NSDictionary *)dictionaryForKey:(NSString *)defaultName;-(id)objectForKey:(NSString *)defaultName;-(NSArray *)arrayForKey:(NSString *)defaultName;