#import <Foundation/Foundation.h>@interface NSUserDefaultUtil : NSObject+(void)PutDefaults:(NSString *)key Value:(id)value;+(id)GetDefaults:(NSString *)key;@end

#import "NSUserDefaultUtil.h"@implementation NSUserDefaultUtil+(void)PutDefaults:(NSString *)key Value:(id)value{ if (key!=NULL&&value!=NULL) {  NSUserDefaults *userDefaults=[NSUserDefaults standardUserDefaults];  [userDefaults setObject:value forKey:key]; }}+(id)GetDefaults:(NSString *)key{ NSUserDefaults *userDefaults=[NSUserDefaults standardUserDefaults]; id obj; if (key!=NULL) {  obj=[userDefaults objectForKey:key]; } return obj;}@end

[NSUserDefaultUtil PutDefaults:@"key" Value:str];self.str = [NSUserDefaultUtil GetDefaults:@"key"];