下拉列表 - 简书


#import <UIKit/UIKit.h>
@class ZMDropDownView;
NS_ASSUME_NONNULL_BEGIN
@protocol ZMDropDownViewDelegate <NSObject>

@optional
-(void)dropDownMenu:(ZMDropDownView *)dropV item:(NSString *)items;

@end



@interface ZMDropDownView : UIView
@property(weak,nonatomic)id<ZMDropDownViewDelegate>delegate;
-(instancetype)initwithDataItems:(NSArray<NSString *>*)dataItems rowHeight:(CGFloat)height;
-(void)unFoldOrFold;
@end


@interface DropDownTableViewCell : UITableViewCell
@property(strong,nonatomic)NSString *title;

@end
NS_ASSUME_NONNULL_END

#import "ZMDropDownView.h"
@interface ZMDropDownView ()<UITableViewDelegate,UITableViewDataSource>
@property(strong,nonatomic)NSArray<NSString *> *menuArr;
@property(strong,nonatomic)UITableView *tb;
@property(assign,nonatomic)CGFloat rowHeight;

@end
@implementation ZMDropDownView
-(UITableView *)tb
{
    if (!_tb) {
        _tb = [[UITableView alloc]initWithFrame:CGRectMake(0, 0, self.bounds.size.width, 0) style:UITableViewStylePlain];
        _tb.rowHeight = UITableViewAutomaticDimension;
        _tb.dataSource = self;
        _tb.delegate = self;
        _tb.layer.cornerRadius = 5;
        _tb.clipsToBounds = YES;
        _tb.layer.borderColor = [UIColor grayColor].CGColor;
        _tb.layer.borderWidth = 1.f;
    }
    return _tb;
}
-(instancetype)initwithDataItems:(NSArray<NSString *>*)dataItems rowHeight:(CGFloat)height;
{
    if (self == [super init]) {
        
        self.menuArr = dataItems;
        self.rowHeight = height;
    }
    return self;
}
-(void)unFoldOrFold;
{
    if ([self.subviews containsObject:self.tb]) {
        [self fold];
    }else
    {
        [self unFold];
    }
}
-(void)fold;{
    CGRect rect =  self.tb.frame;
    [UIView animateWithDuration:0.4 animations:^{
        self.tb.frame = CGRectMake(0, 0, rect.size.width, 0);
    } completion:^(BOOL finished) {
        [self.tb removeFromSuperview];
    }];
    
}
-(void)unFold;{
    [self addSubview:self.tb];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.4];
    self.tb.frame = self.bounds;
    [UIView commitAnimations];
    
}
#pragma mark UITableViewDataSource
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return self.menuArr.count;
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *identifier = @"DropDownTableViewCell";
    DropDownTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
    if (cell == nil) {
        cell = [[DropDownTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
    }
    cell.title = self.menuArr[indexPath.row];
    return cell;
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return self.rowHeight;
}
-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([tableView respondsToSelector:@selector(setLayoutMargins:)]) {
        [tableView setLayoutMargins:UIEdgeInsetsZero];
        [cell setLayoutMargins:UIEdgeInsetsZero];
    }
    if ([tableView respondsToSelector:@selector(setSeparatorInset:)]) {
        [tableView setSeparatorInset:UIEdgeInsetsZero];
        [cell setSeparatorInset:UIEdgeInsetsZero];
    }
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([self.delegate respondsToSelector:@selector(dropDownMenu:item:)]) {
        [self.delegate dropDownMenu:self item:self.menuArr[indexPath.row]];
        [self fold];
    }
}
@end
@interface DropDownTableViewCell ()
@property(strong,nonatomic)UILabel *titleLabel;
@end

@implementation DropDownTableViewCell
-(instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    if (self = [super initWithStyle:style reuseIdentifier:reuseIdentifier]) {
        [self laySUbData];
    }
    return self;
}
-(void)laySUbData{
    UILabel *label = [[UILabel alloc] init];
    label.textColor = [UIColor blackColor];
    //字体大小与对齐方式保持与按钮的titleLabel一致
    label.font = [UIFont systemFontOfSize:14];
    label.textAlignment = NSTextAlignmentLeft;
    [self.contentView addSubview:label];
    
    self.titleLabel = label;
}
-(void)layoutSubviews
{
    [super layoutSubviews];
    self.titleLabel.frame = CGRectMake(5, 0, self.contentView.frame.size.width, self.contentView.frame.size.height);
}
-(void)setTitle:(NSString *)title{
    _title = title;
}

@end

#import <UIKit/UIKit.h>
typedef NS_ENUM(NSInteger,ContentTitleType){
    ContentTitleTypeLeft,
    ContentTitleTypeRight,
    ContentTitleTypeTop,
    ContentTitleTypeBottom
};

NS_ASSUME_NONNULL_BEGIN

@interface DropButton : UIButton
-(instancetype)initWithType:(ContentTitleType)type tempStr:(NSString *)tempStr image:(UIImage *)normalImage highlightImage:(UIImage *)hightLightImage scale:(CGFloat)scale;
@end

#import "DropButton.h"
@interface DropButton()
@property(assign,nonatomic)ContentTitleType titltType;
@property(assign,nonatomic)CGFloat scale;
@end

@implementation DropButton

-(instancetype)initWithType:(ContentTitleType)type tempStr:(NSString *)tempStr image:(UIImage *)normalImage highlightImage:(UIImage *)hightLightImage scale:(CGFloat)scale;
{
    if (self = [super init]) {
        self.titltType = type;
        self.scale = scale;
        
        self.layer.cornerRadius = 2.0;
        self.layer.masksToBounds = YES;
        
        [self setTitle:tempStr forState:UIControlStateNormal];
        [self setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [self setImage:normalImage forState:UIControlStateNormal];
        [self setImage:hightLightImage forState:UIControlStateHighlighted];
        
        self.titleLabel.textAlignment = NSTextAlignmentCenter;
        self.titleLabel.font =[UIFont systemFontOfSize:14];
        self.imageView.contentMode = UIViewContentModeCenter;
                
    }
    return self;
}
-(CGRect)titleRectForContentRect:(CGRect)contentRect;
{
    switch (self.titltType) {
        case ContentTitleTypeLeft:
            return CGRectMake(0, 0, CGRectGetWidth(self.bounds)*self.scale,CGRectGetHeight(self.bounds));
            break;
        case ContentTitleTypeRight:
            return CGRectMake(CGRectGetWidth(self.bounds)*(1-self.scale), 0, CGRectGetWidth(self.bounds)*self.scale,CGRectGetHeight(self.bounds));

            break;
        case ContentTitleTypeBottom:
            return CGRectMake(0, CGRectGetHeight(self.bounds)*(1-self.scale), CGRectGetWidth(self.bounds),CGRectGetHeight(self.bounds)*self.scale);

            break;
        case ContentTitleTypeTop:
            return CGRectMake(0, 0, CGRectGetWidth(self.bounds),CGRectGetHeight(self.bounds)*self.scale);

            break;
        default:
            return [super titleRectForContentRect:contentRect];

            break;
    }
}
-(CGRect)imageRectForContentRect:(CGRect)contentRect;{
    if (self.titltType == ContentTitleTypeTop) {
        return CGRectMake(0, CGRectGetHeight(self.bounds)*self.scale, CGRectGetWidth(self.bounds),CGRectGetHeight(self.bounds)*(1-self.scale));

    }else if (self.titltType == ContentTitleTypeLeft){
        return CGRectMake(CGRectGetWidth(self.bounds)*self.scale, 0, CGRectGetWidth(self.bounds)*(1-self.scale),CGRectGetHeight(self.bounds));

    }else if (self.titltType == ContentTitleTypeRight){
        return CGRectMake(0,0, CGRectGetWidth(self.bounds)*(1-self.scale),CGRectGetHeight(self.bounds));

    }else if (self.titltType == ContentTitleTypeBottom){
        return CGRectMake(0, 0, CGRectGetWidth(self.bounds),CGRectGetHeight(self.bounds)*(1-self.scale));

    }else
       return [super imageRectForContentRect:contentRect];
}
@end

- (void)viewDidLoad {
    [super viewDidLoad];
    self.targetBtn = [[DropButton alloc] initWithType:ContentTitleTypeLeft tempStr:@"items" image:[UIImage imageNamed:@"uc_area_code_pull"] highlightImage:[UIImage imageNamed:@"uc_area_code_pull"] scale:0.5];

    self.targetBtn.frame = CGRectMake(0, 0, 80, 40);
    self.targetBtn.center = self.view.center;
    self.targetBtn.backgroundColor = [UIColor redColor];
    [self.targetBtn addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.targetBtn];
    self.menu = [[ZMDropDownView alloc] initwithDataItems:@[@"item1",@"item2",@"item3",@"item4"] rowHeight:30.f];
    self.menu.delegate = self;
    self.menu.frame = CGRectMake(100, 100, 80, 90);
    self.menu.center = CGPointMake(self.view.center.x, self.view.center.y +70);
    [self.view addSubview:self.menu];
}

- (IBAction)buttonClick:(UIButton *)sender {
    
    [self.menu unFoldOrFold];
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self.menu unFoldOrFold];
}

#pragma mark:
-(void)dropDownMenu:(ZMDropDownView *)dropV item:(NSString *)items;
{
    NSLog(@"-------click---------:%@",items);
}

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