iOS视图滚动的时候控制导航条标题及公告视图的alpha（显示与隐藏）

- (void)setupnavView
{
    navView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, kWidth, kStatusBarHeight)];
                               navView.userInteractionEnabled = YES;//   需要处理点击事件

    
    navView.image = [UIImage imageNamed:@"img_banner_top_ios_top"];
    
    
    //1、添加导航视图UIImageView，并设置背景图片
    
    [self.view addSubview:navView];
    
    
    
    
    
    
    
    navLab = [ControlManager text:@"" font:displayFontSize(18.0f) color:[UIColor whiteColor] alingment:1 fontWithName:@"PingFang-SC-Medium"];
    navLab.frame = CGRectMake(0, kStatusBarHeight - 44, kWidth, 44);
    navLab.backgroundColor = [UIColor clearColor];
    // 1.2 添加导航条标题视图navLab
    [navView addSubview:navLab];
    
    
    
    // 1.3 公告视图
    
        
    [self.noteViw setModel:self.viewModel.noteViweModel];
    


}


- (NoteViw *)noteViw{
    if (nil == _noteViw) {
        NoteViw *tmpView = [[NoteViw alloc]init];
        
        
        
        
        [tmpView setBackgroundColor: HWColor(255, 240, 205)];
        _noteViw = tmpView;
        
        
        
        
        [navView addSubview:_noteViw];
        
        
        
        
        __weak __typeof__(self) weakSelf = self;
        
        [_noteViw mas_makeConstraints:^(MASConstraintMaker *make) {
            

            make.left.right.equalTo(weakSelf.view);
            




            CGRect rectStatus = [[UIApplication sharedApplication] statusBarFrame];
            
            make.top.equalTo(weakSelf.view).offset(rectStatus.size.height);

            make.height.mas_equalTo(kAdjustRatio(k_noteViewH));//32
            


            

        }];

        
        [[_noteViw rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
            
            
            
            
            NSLog(@"跳转到公告详情页");
            
            if(weakSelf.gotoNoteDetailViewControllerblock){
                weakSelf.gotoNoteDetailViewControllerblock(nil);
            }
            
        }];
        
        
        
        
        

        
    }
    
    return _noteViw;
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    navLab.text = @"工作台";
    
    
   double _alpha = 1 - _tableView.contentOffset.y / CGRectGetMaxY(workLab.frame);
    
    
    if (_tableView.contentOffset.y > CGRectGetMaxY(workLab.frame)) {
        
      navLab.alpha = 1;
        
    } else {
        
        navLab.alpha = 1 - _alpha;
        
    }
    
    
    
    self.noteViw.alpha = 1 - navLab.alpha;
    
    
    

    
    
    if (_tableView.contentOffset.y <= 0) {
        
        _tableView.contentOffset = CGPointMake(0, 0);
        
        _tableView.bounces = NO;
    } else {
        
        _tableView.bounces = YES;
    }
}

    vc.navigationItem.leftBarButtonItem.tintColor = [UIColor whiteColor];

        UIButton *tmpView = [[UIButton alloc]init];
        
        UIImage *img = [[UIImage imageNamed:QCTNAVicon_left] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
        
        tmpView.tintColor = UIColor.whiteColor;

typedef NS_ENUM(NSInteger, UIImageRenderingMode) {
    UIImageRenderingModeAutomatic,          // Use the default rendering mode for the context where the image is used
    
    UIImageRenderingModeAlwaysOriginal,     // Always draw the original image, without treating it as a template
    UIImageRenderingModeAlwaysTemplate,     // Always draw the image as a template image, ignoring its color information
} API_AVAILABLE(ios(7.0));

#import <UIKit/UIKit.h>

#import "QCTQCTNoteViweModel.h"

NS_ASSUME_NONNULL_BEGIN

@interface NoteViw : UIButton
@property (nonatomic,copy) QCTQCTNoteViweModel *model;
@property (nonatomic,weak) QMUIMarqueeLabel *titleLable;

@end

//

#import "NoteViw.h"

@interface NoteViw ()
@property (nonatomic,weak) UIButton *btn;

@end

@implementation NoteViw




- (UIButton *)btn{
    if (_btn == nil
        ) {
        UIButton *tmp  = [UIButton new];
        
        [tmp setImage:[UIImage imageNamed:@"icon_daiban_dinghuo"] forState: UIControlStateNormal];
        
        _btn = tmp;
        __weak __typeof__(self) weakSelf = self;
        [self addSubview:tmp];

        [_btn mas_makeConstraints:^(MASConstraintMaker *make) {
            make.centerY.equalTo(weakSelf);
            make.height.width.mas_equalTo(kAdjustRatio(15));
            make.right.equalTo(weakSelf).offset(kAdjustRatio(-16));
        }];
        
    }
    return _btn;
}


- (UILabel *)titleLable{
    if (nil == _titleLable) {
        QMUIMarqueeLabel *tmpView = [[QMUIMarqueeLabel alloc]init];
        _titleLable = tmpView;
        tmpView.textAlignment = NSTextAlignmentCenter;// 跑马灯文字一般都是居中显示，所以 Demo 里默认使用 center
        
//        tmpView.shouldFadeAtEdge = NO;// 关闭渐隐遮罩
//        tmpView.speed = 1.5;// 调节滚动速度
        
        tmpView.textStartAfterFade = YES;// 文字停靠在遮罩的右边



        
        [self addSubview:_titleLable];
        __weak __typeof__(self) weakSelf = self;

        [_titleLable mas_makeConstraints:^(MASConstraintMaker *make) {
//            make.top.bottom.equalTo(weakSelf);
            make.centerY.equalTo(weakSelf);

            make.left.equalTo(weakSelf).offset(kAdjustRatio(10));

            make.right.equalTo(weakSelf.btn.mas_left);
        }];
    }
    return _titleLable;
}


- (void)setModel:(QCTQCTNoteViweModel *)model{
    _model = model;
    [self.btn setImage:[UIImage imageNamed:model.btnImg] forState:UIControlStateNormal];
    [self setuptitle:model.title];
}

- (void)setuptitle:(NSString*)title{
    
    //
    self.titleLable.text = title;
//    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"公告：收款码仅用于在门店消费当面付款使用，为防诈骗，请谨慎向..."];
//    [attributedString addAttribute:NSFontAttributeName value: range:NSMakeRange(0, 34)];
//    [attributedString addAttribute:NSForegroundColorAttributeName value: range:NSMakeRange(0, 34)];
    
    
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:_titleLable.text];//_label.text
    
    
    //    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"可用设备"];
    
    
    [attributedString addAttribute:NSFontAttributeName  value:[UIFont fontWithName:@"PingFang-SC-Medium" size:11.0f]  range:NSMakeRange(0, _titleLable.text.length)];
    //    [attributedString addAttribute:NSForegroundColorAttributeName value:[UIColor colorWithRed:153.0f/255.0f green:153.0f/255.0f blue:153.0f/255.0f alpha:1.0f] range:NSMakeRange(0, _label.text.length)];
    
    [attributedString addAttribute:NSForegroundColorAttributeName value:[UIColor colorWithRed:255.0f/255.0f green:162.0f/255.0f blue:29.0f/255.0f alpha:1.0f] range:NSMakeRange(0, _titleLable.text.length)];
    
    
    _titleLable.attributedText = attributedString;

}


@end