存储在字典中的内容到判断输出时就为空

#import <Foundation/Foundation.h>
#import "UserAdministration.h"
@interface UsernameandPassword : NSObject
@property(nonatomic,strong)NSString *Username;
@property(nonatomic,strong)NSString *Password;
@property(nonatomic,strong)UserAdministration *userAd;
@property(nonatomic,strong)NSString *addvideoID;
@property(nonatomic,strong)NSString *addvideoname;
@property(nonatomic,strong)NSMutableDictionary *addv;
-(void)UserSignin;
-(void)FunctionSelection;
-(id)initWithAddv:(NSMutableDictionary *)addv AddvideoID:(NSString *)addvideoID Addvideoname:(NSString *)addvideoname;
@end

#import "UsernameandPassword.h"

#define NSLog(FORMAT, ...) fprintf(stderr,"%s",[[NSString   stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String])


@implementation UsernameandPassword

-(id)initWithAddv:(NSMutableDictionary *)addv AddvideoID:(NSString *)addvideoID Addvideoname:(NSString *)addvideoname{

    self = [super init];
    if (self) {

        self.addv = addv;
        self.addvideoID = addvideoID;
        self.addvideoname = addvideoname;

    }
    return self;
}



-(void)UserSignin{
    
    
    //用户登录
    NSLog(@"******************iOS学习系统登录界面******************\n");
    NSLog(@"是否登录:\n1登录\n2不登录\n");
    //登录选项
    int LoginOptions = 0;
    scanf("%d",&LoginOptions);
    
    
    if (LoginOptions == 1) {
            //用户名
            NSLog(@"请输入登录用户名:");
            
            char buffer1[1000];
            
            scanf("%s",buffer1);
            
            NSString * youname = [NSString stringWithUTF8String:buffer1];
            
            //用户密码
            NSLog(@"请输入登录密码:");
            
            char buf2[1000];
            
            scanf("%s",buf2);
            
            NSString * youpassword = [NSString stringWithUTF8String:buf2];
        
            //判断输入的用户名和密码是否和注册时的一致
            if(youname == self.userAd.flag && youpassword == self.userAd.fla){
                
                NSLog(@"\n登录成功\n");
                NSLog(@"******************iOS学习系统功能选择界面******************\n");
                NSLog(@"请输入要选择的功能\n");
                
            }else{
                NSLog(@"用户名或密码错误，请重新输入\n");
                [self UserSignin];
            }
        
    }else{
        
        NSLog(@"退出学习系统\n");
    }
}



-(void)FunctionSelection{
    NSMutableDictionary *addv = [[NSMutableDictionary alloc]init];
    //登录后功能选择:1>1>2>1    这样就可以一直循环
    
    //登录后操作
    NSLog(@"1 观看iOS学习视频\n2 下载iOS学习资料\n3 直接退出\n");
    //功能选择
    int a = 1;
    int b = 0;
    while (a > b) {
        
    
    int Function = 0;
    scanf("%d",&Function);
    
    if (Function == 1) {
        
        NSLog(@"视频为空\n观看iOS学习视频中……\n请输入要选择的功能:\n");
        NSLog(@"1 观看iOS学习视频\n2 下载iOS学习资料\n3 直接退出\n");
        //观看视频
        int WatchVideo = 0;
        scanf("%d",&WatchVideo);
        
        if (WatchVideo == 1) {
            NSLog(@"1 查询所有iOS视频\n2 通过ID选择播放某一iOS视频\n3 添加一个新的iOS视频\n4 删除某一iOS视频\n");
            //通过ID播放视频
            int IdPlay = 0;
            scanf("%d",&IdPlay);
            if (IdPlay == 1) {
                NSLog(@"观看iOS学习视频中……\n");
            }else if (IdPlay == 2){
                
                NSLog(@"请输入要选择观看的视频ID\n");
                //播放ID视频
                int VideoiD = 0;
                scanf("%d",&VideoiD);
                if (VideoiD == 1) {
                    NSLog(@"你查找的视频不存在\n观看学习视频中……\n请输入要选择的功能:\n");
                    NSLog(@"1 观看iOS学习视频\n2 下载iOS学习资料\n3 直接退出\n");
                }else if(VideoiD == self.addvideoID){
                    NSArray *str1 = [self.addv valueForKey:self.addvideoID];
                    NSLog(@"%@\n",str1);
                    
                    [self FunctionSelection];
                }
            }else if (IdPlay == 3){
                
                NSLog(@"请输入视频ID\n");
                
                char adv[1000];
                scanf("%s",adv);
                self.addvideoID = [NSString stringWithUTF8String:adv];
                
                NSLog(@"请输入视频名称\n");
                
                char advn[1000];
                scanf("%s",advn);
                self.addvideoname = [NSString stringWithUTF8String:advn];
               
                
                [addv setValue:self.addvideoname forKey:self.addvideoID];
                
                NSLog(@"%@",addv);
                [self FunctionSelection];
                
            }else if (IdPlay == 4){
                
                NSLog(@"请输入需要删除的视频ID\n");
                [addv removeObjectForKey:self.addvideoID];
                [self FunctionSelection];
            }
            
        }
    }else if (Function == 2){
        
        NSLog(@"1 下载所有iOS视频\n2 通过ID选择下载某一iOS视频\n");
        
    }else if (Function == 3){
        
        NSLog(@"退出\n");
        
    }
        a++;
    }
    
}

@end