各种“传值”

传值，什么样的值才叫值？我开始始终认为传值值得就是将一个页面textflied的text传到另外一个页面，那叫传值，哎，太年轻啊，最近各种传值，说说薄弱的一点点经验吧，我觉得最好用的还属block吧，个人比较喜欢，协议也不错，协议和block用法挺像的而且比block麻烦，就不写啦，通知一对多，比如在软件中想写个设置背景图片什么的简直是利器，至于单例也有传值的功能，共享单例,在用FMDB数据库时也是很好用滴，剩下的传值好像还有个正向传值，也就是变量传值，那个很简单就不写了，好吧，我承认我写的都很简单，欢迎大能补充

 

FMDB，共享单例

+ (instancetype)sharedInstance{
    
    static TimeTableDBmanager *s_dbManager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        
        s_dbManager = [[TimeTableDBmanager alloc]init];
    });
    return s_dbManager;
}

通知传值设置所有页面的背景图片

将一张图片直接转为NSData，然后，好吧，将就存在NSUserDefaut里面吧，因为要实现数据持久化，不然下次进来就没了

- (void)notifacation:(UIImage *)image{
    
    NSData *imageData = UIImagePNGRepresentation(image);
    
    [[NSUserDefaults standardUserDefaults] setObject:imageData forKey:@"image"];
    [[NSUserDefaults standardUserDefaults] synchronize];
    
    
    NSDictionary *dic = [[NSDictionary alloc]initWithObjectsAndKeys:image,@"picname", nil];
    
    NSNotification *notifaction = [NSNotification notificationWithName:@"tongzhi" object:nil userInfo:dic];
    
    [[NSNotificationCenter defaultCenter]postNotification:notifaction];
    
    image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    
    self.BackgroundImageView.image = image;
}

//将以下代码封装起来就可以在各个页面设置背景图片啦，好吧，是不是有点low啊

 NSData *imageData;
    imageData = [[NSUserDefaults standardUserDefaults] objectForKey:@"image"];
    
    //UIImage *image = [NSKeyedUnarchiver unarchiveObjectWithData:imageData];
    UIImage *image = [UIImage imageWithData:imageData];
    
     image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    
    [self.BackgroundView setImage:[image applyBlurWithRadius:10 tintColor:[UIColor colorWithWhite:1 alpha:0.5] saturationDeltaFactor:1.8 maskImage:nil]];
    
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(notifacation:) name:@"tongzhi" object:nil];

 

- (void)notifacation:(NSNotification *)text{
    
    UIImage *picname = text.userInfo[@"picname"];
    
     picname = [picname imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    
    [self.BackgroundView setImage:[picname applyBlurWithRadius:10 tintColor:[UIColor colorWithWhite:1 alpha:0.5] saturationDeltaFactor:1.8 maskImage:nil]];
    
}

block块不止可以传值，他貌似可以传任何想传的东西，最好用的莫过于，只有触发时才回到赋值的地方执行代码了，而且其中一个特性也是很强大，捕获外部变量，有时候可以直接把传值都省了，如果有大量数据要创建，不想在页面出现时就创建，那就在点击时给block块传值创建，那样代码会很漂亮，好吧，表达不清直接上代码，当然这是才开始接触时写的一个Demo了

//点击

- (void)addTapGestureRecognizer{
    self.userInteractionEnabled = YES;
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handletap:)];
    
    [self addGestureRecognizer:tap];
}

- (void)handletap:(UITapGestureRecognizer *)tapGesture{
   
    if (self.clickAction) {
        self.clickAction(self);
    }
}

 

#import "ViewController.h"
#import "ClickUIimageView.h"
#import "DetalViewController.h"

#define IMAGE_PADDING 5
#define CONTENT_VIEW_W  (375-5*IMAGE_PADDING)/4
#define CONTENT_VIEW_H  CONTENT_VIEW_W*5.0/3

@interface ViewController ()
{
    UIScrollView *_scrollView;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor cyanColor];
    
    //注意：由于坐标是从导航栏下开始，所以scrollview的高度667-64
    _scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width,603)];
//    
//    UIImageView *imageview = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"2_1.jpg"]];
//    
//    imageview.frame = self.view.bounds;
      //  [_scrollView addSubview:imageview];
    
    self.navigationController.navigationBar.translucent = NO;
    
    //当 Scrollview 和 navigationController 一起使用时，默认情况下UINavigationController会对UIScrollView的内边距距离进行调整，目的是防止UIscrollView的内容被覆盖
    //凡是从UIScrollView继承的子类都有这个问题
    //通过下面这句话可以消除这种默认调整
    self.automaticallyAdjustsScrollViewInsets = NO;
    
    NSString *plistFile = [[NSBundle mainBundle]pathForResource:@"AlbumData" ofType:@"plist"];
    
    NSArray *ablumArray = [NSArray arrayWithContentsOfFile:plistFile];
    
    for (int i = 0; i < ablumArray.count; i++) {
        NSDictionary *dic = [ablumArray objectAtIndex:i];
        NSString *imageName = [NSString stringWithFormat:@"%@.jpg",dic[@"NAME"]];
        
        ClickUIimageView *imageView1 = [[ClickUIimageView alloc]initWithImage:[UIImage imageNamed:imageName] title:dic[@"TITLE"] ClickAction:^(ClickUIimageView *imageView) {
            //点击之后处理的代码
            
            DetalViewController *detailViewController = [[DetalViewController alloc]init];
            
            detailViewController.imageTitle = dic[@"TITLE"];
            detailViewController.imageName = [NSString stringWithFormat:@"%@.jpg",dic[@"NAME"]];
            //detailViewController.index = i;
            detailViewController.completeBlock = ^(NSString *title){
                [imageView updateTitle:title];
            };
            [self.navigationController pushViewController:detailViewController animated:YES];
            
        }];
        
        
        imageView1.frame = CGRectMake(IMAGE_PADDING+(CONTENT_VIEW_W+IMAGE_PADDING)*(i%4), IMAGE_PADDING+(CONTENT_VIEW_H+IMAGE_PADDING)*(i/4), CONTENT_VIEW_W, CONTENT_VIEW_H);
        
        //找到最后一个imageView
        if (i == ablumArray.count-1) {
            _scrollView.contentSize = CGSizeMake(_scrollView.bounds.size.width,CGRectGetMaxY(imageView1.frame)+40);
        }
        [_scrollView addSubview:imageView1];
    }
    
    [self.view addSubview:_scrollView];
}

 

转载于:https://www.cnblogs.com/Lvfengxian/p/4902846.html