UserInfoManager.h文件    #import <UIKit/UIKit.h>      @interface UserInfoManager : NSObject    +(BOOL)initWithDic:(NSDictionary *)dic;    +(NSDictionary *)readUserInfo;    +(BOOL)isFirstLoad;    +(BOOL)updateWithObject:(id)obj forKey:(NSString *)key;    +(BOOL)updateWithBool:(BOOL)boolValue forKey:(NSString *)key;    +(BOOL)updateWithFloat:(float)floatValue forKey:(NSString *)key;    @end    UserInfoManager.m文件    #import "UserInfoManager.h"    #import "Foundation/Foundation.h"      @interface UserInfoManager ()      @end      @implementation UserInfoManager      //是否第一次登陆    +(BOOL)isFirstLoad    {        if([[NSUserDefaults standardUserDefaults] objectForKey:@"isFirstLoad"])        {            [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"isFirstLoad"];            return YES;        }          else        {            return NO;        }    }    //创建一个NSUserDefaults对象用以保存数据    +(BOOL)initWithDic:(NSDictionary *)dic    {        NSUserDefaults * userInfoManager = [NSUserDefaults standardUserDefaults];        if (dic == Nil) {            return NO;        }        NSArray * keys = [dic allKeys];        for(int i = 0;i < [keys count];i ++)        {            [userInfoManager setObject:[dic objectForKey:[keys objectAtIndex:i]] forKey:[keys objectAtIndex:i]];        }        return [userInfoManager synchronize];    }      //读取数据    +(NSDictionary *)readUserInfo    {       NSUserDefaults * userInfoManager = [NSUserDefaults standardUserDefaults];         return [userInfoManager dictionaryRepresentation];    }      //更改某项数据    +(BOOL)updateWithObject:(id)obj forKey:(NSString *)key    {        [[NSUserDefaults standardUserDefaults] setObject:obj forKey:key];       return  [[NSUserDefaults standardUserDefaults] synchronize];    }      +(BOOL)updateWithBool:(BOOL)boolValue forKey:(NSString *)key    {        [[NSUserDefaults standardUserDefaults] setBool:boolValue  forKey:key];        return  [[NSUserDefaults standardUserDefaults] synchronize];    }      +(BOOL)updateWithFloat:(float)floatValue forKey:(NSString *)key    {        [[NSUserDefaults standardUserDefaults] setFloat:floatValue  forKey:key];        return  [[NSUserDefaults standardUserDefaults] synchronize];    }    @end