iOS UITableView组头组尾小结

项目中我们会经常用到UITableView组头组尾，下边简述下三种方式（组头为例,组尾同理）

一、继承UITableViewHeaderFooterView（正规写法，有复用，适合组头频繁出现的情况）

1、自定义SectionHeaderView

@interface SectionHeaderView : UITableViewHeaderFooterView
@property (nonatomic, strong) UIView *bgView;
@property (nonatomic, strong) UILabel *titleLab;
@end

@implementation SectionHeaderView

#pragma mark - System
- (instancetype)initWithReuseIdentifier:(NSString *)reuseIdentifier {
    self = [super initWithReuseIdentifier:reuseIdentifier];
    if (self) {
        [self initData];
        [self initUI];
    }
    return self;
}

#pragma mark - Init Data

- (void)initData {
    
}

#pragma mark - Init UI

- (void)initUI {
    
    UIView *bgView = [[UIView alloc]init];
    bgView.backgroundColor = XZWL_COLOR_FFFFFF;
    [self.contentView addSubview:bgView];
    [bgView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.contentView).insets(UIEdgeInsetsMake(0, 15, 0, 15));
    }];
    self.bgView = bgView;
    
    UIImageView *icon = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"career_addcustomer_sectionHead"]];
    [bgView addSubview:icon];
    [icon mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(bgView).offset(15);
        make.top.equalTo(bgView.mas_top).offset(17);
        make.width.height.mas_equalTo(20);
    }];
    
    self.titleLab = [[UILabel alloc]init];
    self.titleLab.textColor = XZWL_COLOR_333333;
    self.titleLab.font = FF_PFM_ICOME(16);
    self.titleLab.numberOfLines = 2;
    self.titleLab.lineBreakMode = NSLineBreakByCharWrapping;
    [bgView addSubview:self.titleLab];
    [self.titleLab mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(icon.mas_right).offset(15);
        make.right.equalTo(bgView.mas_right).offset(-15);
        make.height.mas_greaterThanOrEqualTo(20);
        make.top.equalTo(icon);
    }];
    
    UIView *line = [[UIView alloc]init];
    line.backgroundColor = XZWL_COLOR_EBEBEB;
    [bgView addSubview:line];
    [line mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.bottom.equalTo(bgView);
        make.height.mas_equalTo(0.5);
    }];
}

2、使用

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
    SectionHeaderView *headerView = [tableView dequeueReusableHeaderFooterViewWithIdentifier:@"Test"];
    if (headerView == nil) {
        headerView = [[SectionHeaderView alloc] initWithReuseIdentifier:@"Test"];
        
    }
    
    headerView.titleLab.text = @"这是组头";
    return headerView;
}
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
    
    return 50;
}

二、自定义UIView（野路子，适合简单的组头，或者只出现一次，不重复使用的）

1、创建

@interface SectionHeader : UIView
@property (nonatomic, strong) UILabel *titleLable;
@end

@implementation SectionHeader

#pragma mark - System

- (instancetype)initWithFrame:(CGRect)frame {
     
    self = [super initWithFrame:frame];
    if (self) {
        [self initData];
        [self initUI];
    }
    return self;
}

#pragma mark - Init Data

- (void)initData {
 }

#pragma mark - Init UI

- (void)initUI {
    UILabel *msgLabel = [[UILabel alloc] init];
    msgLabel.frame = CGRectMake(15, 0, 200, 16);
    msgLabel.font = FF_PFM_ICOME(17);
    msgLabel.textColor = XZWL_COLOR_333333;
    self.backgroundColor = [UIColor clearColor];
    [self addSubview:msgLabel];
    self.titleLable = msgLabel;
}


@end

2、使用

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
    
   return 36;
}

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {

//不要试图使用懒加载创建，然后动态改变title，这样会出问题，因为每一个组头都需要一个对象，正规写法是有复用机制的

SectionHeader *tableSectionHederView = [[SectionHeader alloc] init];

    NSString *title = @"Test1";
    if (section == 2) {
       title = @"Test2";
    }
    tableSectionHederView.titleLable.text = title;
    return tableSectionHederView;
    
}

三、直接返回UIView（野路子，适合极简单的，与二相比，未封装，冗余）

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
   return 44.0;
    
}

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
    
    UIView *headerView =  [[UIView alloc] init];
    headerView.frame = CGRectMake(0, 0, LL_ScreenWidth, 44.0);
    headerView.backgroundColor = THEME_COLOR_WHITE;
    headerView.clipsToBounds = YES;
    
    UILabel *titleLabel =  [[UILabel alloc] init];
    titleLabel.frame = CGRectMake(15, 13, LL_ScreenWidth - 150, 18);
    titleLabel.font = [UIFont systemFontOfSize:17];
    titleLabel.numberOfLines = 1;
    titleLabel.textColor = XZWL_COLOR_999999;
    titleLabel.textAlignment = NSTextAlignmentLeft;
    [headerView addSubview:titleLabel];
    
    UIView *lineView =  [[UIView alloc] init];
    lineView.frame = CGRectMake(0, 43.5, LL_ScreenWidth, 0.5);
    lineView.backgroundColor = XZWL_COLOR_EBEBEB;
    [headerView addSubview:lineView];
    
    return headerView;
}