开发过程中底部弹窗视图在很多处会被用到，所以今天写一个简易的底部弹窗视图

底部弹出视图

1.先分析都有哪些控件
底部蒙层 maskView（UIView），弹出视图部分：由里到外分别是：scrollview(可向下滑动关闭)->contentView(UIView用来盛放里面所有视图的容器)->tableview（容器里面的控件）

2.先上自定义view实现的代码(使用mansory布局)

#define SCREEN_WIDTH [[UIScreen mainScreen] bounds].size.width
#define SCREEN_HEIGHT [[UIScreen mainScreen] bounds].size.height
#define scrollHeight 500
#import <Masonry/Masonry.h>

@interface ZKMyView()<UIScrollViewDelegate,UITableViewDelegate,UITableViewDataSource>

@property (nonatomic,strong)UIView *maskView;
@property (nonatomic,strong)UIScrollView *scrollView;
@property (nonatomic,strong)UIView *contentViews;
@property (nonatomic,strong)UIView *topSlideView;
@property (nonatomic,strong)UILabel *titleLabel;
@property (nonatomic,strong)UITableView *tableView;

@end
@implementation ZKMyView

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
        [self createUI];
    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    [self setNeedsUpdateConstraints];

    [UIView animateWithDuration:0.4 animations:^{
        [self.scrollView mas_updateConstraints:^(MASConstraintMaker *make) {
            make.bottom.equalTo(self).with.offset(0);
        }];
       self.maskView.alpha = 1;
        [self layoutIfNeeded];
    }];
}

-(void)createUI{
    self.maskView = [[UIView alloc]init];
    self.maskView.alpha = 0;
    self.maskView.userInteractionEnabled = YES;
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(clickToHide)];
    
    [self.maskView addGestureRecognizer:tap];

    [self addSubview:self.maskView];
    
    [self.maskView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self);
    }];
    
    UIBlurEffect * blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
    
    UIVisualEffectView * effectView = [[UIVisualEffectView alloc]initWithEffect:blurEffect];
    effectView.userInteractionEnabled = NO;
    
    effectView.alpha = 0.6;
    
    [self.maskView addSubview:effectView];
    
    
    [effectView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.maskView);
    }];
    
    
    self.scrollView = ({
        UIScrollView *scrollView = [[UIScrollView alloc]init];
        scrollView.delegate = self;
        scrollView.backgroundColor = [UIColor clearColor];
        scrollView.showsVerticalScrollIndicator = NO;
        scrollView.layer.cornerRadius = 10;
        scrollView.alwaysBounceVertical = NO;
        scrollView;
    });
    [self addSubview:self.scrollView];
    
    
    [self.scrollView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right .equalTo(self);
        make.height.mas_equalTo(scrollHeight);
        make.bottom.equalTo(self).offset(scrollHeight);
    }];

    
    self.contentViews = ({
        UIView *aView = [[UIView alloc] init];
        aView.backgroundColor = [UIColor whiteColor];
        aView;
    });
    
    [self.scrollView addSubview:self.contentViews];
    
    [self.contentViews mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.mas_equalTo(0);
        make.width.equalTo(self.scrollView);
        make.height.mas_equalTo(scrollHeight);
    }];

    self.topSlideView = ({
        UIView *aView = [[UIView alloc] init];
        aView.backgroundColor = [UIColor colorWithWhite:0 alpha:0.2];
        aView.layer.cornerRadius = 2.5;
        aView.layer.masksToBounds = true;
        aView;
    });

    [self.contentViews addSubview:self.topSlideView];
    
    [self.topSlideView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerX.mas_equalTo(0);
        make.top.mas_equalTo(15);
        make.width.mas_equalTo(36);
        make.height.mas_equalTo(5);
    }];

    self.titleLabel = ({
        UILabel *label = [[UILabel alloc]init];
        label.text = @"hello";
        label;
    });
    [self.contentViews addSubview:self.titleLabel];
    
    [self.titleLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.contentViews).offset(32 );
        make.left.equalTo(self.contentViews).offset(16 );
        make.right.equalTo(self.contentViews).offset(-58 );
        make.height.mas_equalTo(24);
    }];
    
    self.tableView = ({

        UITableView *tableView = [[UITableView alloc]initWithFrame:CGRectZero style:UITableViewStyleGrouped];
        
        tableView.dataSource = self;
        
        tableView.delegate = self;
        
        tableView.showsVerticalScrollIndicator = NO;
        
        tableView.editing = YES;
        
        tableView.backgroundColor = [UIColor whiteColor];
        
        tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
        
         
        tableView;
    });
     
    [self.contentViews addSubview:self.tableView];
    
    [self.tableView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.contentViews);
        make.top.equalTo(self.topSlideView.mas_bottom);
        make.bottom.equalTo(self.contentViews.mas_bottom);
    }];
    
}

//点击背景（蒙版）隐藏（视图）
-(void)clickToHide{
    [UIView animateWithDuration:0.4 animations:^{
        [self.scrollView mas_updateConstraints:^(MASConstraintMaker *make) {
            make.bottom.equalTo(self.mas_bottom).offset(500);
        }];
    }];
    
    [UIView animateWithDuration:0.3 animations:^{
        self.maskView.alpha = 0;
        [self layoutIfNeeded];
    } completion:^(BOOL finished) {
        [self removeFromSuperview];
    }];
}

tableviewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 50;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellID = @"cellID";
    UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:cellID];
    if (!cell) {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellID];
    }
    cell.textLabel.text = [NSString stringWithFormat:@"%ld",indexPath.row];
    return cell;
}

实现scrollview代理

//此处是scrollview不允许向上滑动
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
    
    if ([scrollView isEqual:self.scrollView]) {
        
        if (scrollView.contentOffset.y > 0) {
            scrollView.contentOffset = CGPointMake(0, 0);
        }
        
    }else{
        if (scrollView.contentOffset.y <= 0) {
            
            scrollView.contentOffset = CGPointMake(0, 0);
            self.scrollView.alwaysBounceVertical = true;
        }else{
            self.scrollView.alwaysBounceVertical = false;
//            self.topLineView.hidden = NO;
        }
    }
     
}

//此处是scrollview向下滑动超过80则关闭视图
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset{
     
    if (scrollView.contentOffset.y <= -80) {
        [self clickToHide];
    }
}
@end

使用：在要用到的地方

    self.zkView = [[ZKMyView alloc]initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT)];
    [self.view addSubview:self.zkView];