iOS：类似于网易云音乐的刷新条目显示弹框

//
//  ShowMessageView.h
//  ShowMessageTest
//
//  Created by 夏远全 on 2018/3/22.
//  Copyright ? 2018年 夏远全. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ShowMessageView : UIView

//创建显示弹框（这个直接放在基类中创建，并将该实例对象暴露给子类使用，vc的系统导航栏没有隐藏掉）
+(instancetype)createShowMessageViewInViewController:(UIViewController *)vc;

//创建显示弹框（这个直接放在基类中创建，并将该实例对象暴露给子类使用，vc的系统导航栏被隐藏掉了，传入vc自定义的导航栏customNav）
+(instancetype)createShowMessageViewInViewController:(UIViewController *)vc customNav:(UIView *)customNav;

//显示消息 (刷新结束后调用)
-(void)showMessage:(NSString *)message;

//隐藏消息 (需要在基类的viewWillDisappear调用一次就行了)
-(void)hideMessage;

@end

//
//  ShowMessageView.m
//  ShowMessageTest
//
//  Created by 夏远全 on 2018/3/22.
//  Copyright ? 2018年 夏远全. All rights reserved.
//

#import "ShowMessageView.h"
#import <Masonry.h>

#define isIphoneX_YML (kScreenWidth == 375.0 && kScreenHeight == 812.0) //没有横屏模式才能这么判断
#define kStatusBarHeight (isIphoneX_YML ? 44.0 : 20.0)
#define kNavigationHeight 44.0
#define kNavigationAndStatusBarHeight    (kStatusBarHeight + kNavigationHeight)

@interface ShowMessageView ()
@property (nonatomic, strong) UILabel *messageLabel;
@property (nonatomic, assign) CGFloat messsageWidth;
@end

@implementation ShowMessageView


#pragma mark - life cycle
+(instancetype)createShowMessageViewInViewController:(UIViewController *)vc
{
    ShowMessageView *messageView = [[self alloc] initWithFrame:CGRectMake(0, kNavigationAndStatusBarHeight-40, 200, 40)];
    
    messageView.backgroundColor = [UIColor clearColor];
    messageView.alpha = 0;
    messageView.hidden = YES;
    
    messageView.centerX  = vc.navigationController.navigationBar.centerX;
    
    [messageView setShadowForView:messageView];
    
    [vc.navigationController.navigationBar addSubview:messageView];

    [vc.navigationController.navigationBar sendSubviewToBack:messageView];
    
    [messageView setup];
    
    return messageView;
}

+(instancetype)createShowMessageViewInViewController:(UIViewController *)vc customNav:(UIView *)customNav;{
    
    ShowMessageView *messageView = [[self alloc] initWithFrame:CGRectMake(0, kNavigationAndStatusBarHeight-40, 200, 40)];
    
    messageView.backgroundColor = [UIColor clearColor];
    messageView.alpha = 0;
    messageView.hidden = YES;
    
    messageView.centerX  = customNav.centerX;
    
    [ShadowUtility setShadowForView:messageView];
    
    [customNav addSubview:messageView];
    
    [customNav sendSubviewToBack:messageView];
    
    [messageView setup];
    
    return messageView;
}

-(void)setup
{
    [self setDefalut];
    [self addSubViews];
    [self setupSubviewsConstraints];
}

-(void)setDefalut
{
    
}

#pragma mark - add subViews
-(void)addSubViews
{
    [self addSubview:self.messageLabel];
}


#pragma mark - layout subviews
-(void)setupSubviewsConstraints
{
    [self.messageLabel mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.centerX.equalTo(self.mas_centerX);
        make.centerY.equalTo(self.mas_centerY);
        make.height.equalTo(self.mas_height);
        if (self.messsageWidth > 0) {
            make.width.equalTo(@(MAX(100, self.messsageWidth)+20));
        }
    }];
}


#pragma mark - event response

#pragma mark - public methods
-(void)showMessage:(NSString *)message{
    
    self.messageLabel.text = message;
    
    if (message.length > 0) {
        self.messsageWidth = [message boundingRectWithSize:CGSizeMake(MAXFLOAT, 40) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:16]} context:nil].size.width;
        [self setupSubviewsConstraints];
    }
    
    if (self.alpha == 0) {
        
        self.hidden = NO;
        
        [UIView animateWithDuration:0.8 animations:^{
    
            self.alpha = 1.0;
            self.transform = CGAffineTransformMakeTranslation(0,40+10);
            
        } completion:^(BOOL finished) {
            
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                
                [UIView animateWithDuration:0.3 animations:^{
                    
                    self.alpha = 0;
                    
                } completion:^(BOOL finished) {
                    
                    self.hidden = YES;
                    self.transform = CGAffineTransformIdentity;
                }];
    
            });
            
        }];
    }
    
}

-(void)hideMessage{
    self.alpha = 0;
    self.transform = CGAffineTransformIdentity;
}

#pragma mark - private methods
- (void)setShadowForView:(UIView *)view
{
    view.layer.shadowColor = HEXCOLOR(0xaeaeae).CGColor;
    view.layer.shadowOffset = CGSizeMake(0, 0);
    view.layer.shadowRadius = 4.0;
    view.layer.shadowOpacity = 0.2;
    view.layer.shouldRasterize = YES;
    view.layer.rasterizationScale = [UIScreen mainScreen].scale;
}

#pragma mark - getters and setters
-(UILabel *)messageLabel{
    if (!_messageLabel) {
        _messageLabel = [[UILabel alloc] init];
        _messageLabel.layer.cornerRadius = 20;
        _messageLabel.layer.masksToBounds = YES;
        _messageLabel.font = [UIFont systemFontOfSize:16];
        _messageLabel.textAlignment = NSTextAlignmentCenter;
        _messageLabel.textColor = [UIColor whiteColor];
        _messageLabel.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.7];
    }
    return _messageLabel;
}

@end