参考:对UIView的扩展(Category)

实现的效果

头部标题栏.png

.h 文件

#import <UIKit/UIKit.h>

@interface YYFirstViewController : UIViewController

@end

.m 文件

#import "YYFirstViewController.h"
#import "UIView+YYExtension.h" // 引入头文件

@interface YYFirstViewController ()
@property (nonatomic, strong)UIView *indicatorView; // 指示器
@property (nonatomic, strong)UIButton *selectedBtn; //选中按钮
@end

@implementation YYFirstViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // 初始化顶部标题栏
    [self setUpTitleView];
    
}

#pragma mark -初始化顶部标题栏
- (void)setUpTitleView{
    CGFloat y =  self.navigationController.navigationBar.height + [UIApplication sharedApplication].statusBarFrame.size.height;
    UIView *titleView = [[UIView alloc]initWithFrame:CGRectMake(0, y, self.view.width, 35)];
//    titleView.backgroundColor = [UIColor whiteColor];
//    titleView.alpha = 0.8; // 会让内部所有内容半透明
    // 设置颜色半透明(三种方式)
    titleView.backgroundColor = [[UIColor whiteColor] colorWithAlphaComponent:0.7];
//    titleView.backgroundColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.7];
//    titleView.backgroundColor = [UIColor colorWithWhite:1.0 alpha:0.7];
    [self.view addSubview:titleView];
    
    
    // 创建指示器
    UIView *indicatorView = [[UIView alloc]init];
    indicatorView.backgroundColor = [UIColor redColor];
    indicatorView.height = 2; //(对UIView的扩展(Category))
    indicatorView.y = titleView.height - 2;//(对UIView的扩展(Category))
    self.indicatorView = indicatorView;
    [titleView addSubview:indicatorView];
    
    // 添加子标签
    NSArray *titles= @[@"全部",
                       @"视频",
                       @"声音",
                       @"图片",
                       @"段子"];
    CGFloat btnWidth = titleView.width / titles.count; //(对UIView的扩展(Category))
    CGFloat btnHeight = titleView.height;
    CGFloat btnY = 0.0;
    for (int i = 0; i < titles.count; i ++) {
        CGFloat btnX = i * btnWidth;
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
        btn.frame = CGRectMake(btnX, btnY, btnWidth, btnHeight);
        [btn setTitle:titles[i] forState:UIControlStateNormal];
        [btn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
        [btn setTitleColor:[UIColor redColor] forState:UIControlStateDisabled];
        btn.titleLabel.font = [UIFont systemFontOfSize:14];
        [btn addTarget:self action:@selector(titleBtnAction:) forControlEvents:UIControlEventTouchUpInside];
        [titleView addSubview:btn];
        
        if (i == 0) {
            [btn layoutIfNeeded]; // 如果不加这句话,btn 的titleLabel的宽度为0(强制刷新一次)
            [self titleBtnAction:btn];
        }
    }
}

/**
 标题栏选中
 */
- (void)titleBtnAction:(UIButton *)btn{
    
    [UIView animateWithDuration:0.25 animations:^{
        // 交换三部曲
        self.selectedBtn.enabled = true;
        btn.enabled = false;
        self.selectedBtn = btn;
        // 交换三部曲
        /** 这种方法有问题
        self.selectedBtn.selected = false;
        btn.selected = true;
        self.selectedBtn = btn;
        */
        // 改变指示器
        self.indicatorView.width = btn.titleLabel.width;//1.重点  2.(对UIView的扩展(Category))
        self.indicatorView.centerX = btn.centerX; //(对UIView的扩展(Category))
    }];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

@end