UI基础 - UISegmentedControl

■ 简言

1. UISegmentedControl 分段控件提供一栏按钮，也被称为按钮栏

■ 使用方式

#import "ViewController.h"
#import "AppDelegate.h"
@interface ViewController()
@end

@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor blackColor];
    
    NSArray *titles = [NSArray arrayWithObjects:@"男人",@" ? ",@"女人", nil];
    // 传入的数组可以是字符串，也可以是 UIImage对象 图片
    UISegmentedControl *segmented = [[UISegmentedControl alloc] initWithItems:titles];
    [segmented setFrame:CGRectMake(20, 100, self.view.frame.size.width - 40, 45)];
    segmented.selectedSegmentIndex = 1;// 默认选中下标：？
    [segmented setSelectedSegmentTintColor:[UIColor greenColor]]; // 选中背景颜色
    [segmented setWidth:80 forSegmentAtIndex:1];    // 给某一位置的分段单独指定宽度，其余宽度均分给每个分段
    segmented.backgroundColor = [UIColor cyanColor];// 背景颜色
    segmented.momentary = NO;// 默认 NO：YES 表示按钮按下后很快恢复（撤销选中状态）
    
    // 选中字体颜色
    NSDictionary *selectedTextAttributes = @{NSFontAttributeName:[UIFont boldSystemFontOfSize:20],
                                             NSForegroundColorAttributeName: [UIColor redColor]};
    [segmented setTitleTextAttributes:selectedTextAttributes forState:UIControlStateSelected];
    // 常态字体颜色
    NSDictionary *unselectedTextAttributes = @{NSFontAttributeName:[UIFont boldSystemFontOfSize:16],
                                               NSForegroundColorAttributeName: [UIColor yellowColor]};
    [segmented setTitleTextAttributes:unselectedTextAttributes forState:UIControlStateNormal];
    [segmented addTarget:self action:@selector(changeSegment:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:segmented];
    
    // UISegmentedControl 在 iOS 13中有了新的外观，用于更改分段控件的颜色的现有代码不再像以前那样工作
    // 在 iOS 13之前，您可以设置 tintColo；在 iOS 13 后，tintColor 什么也不做
    segmented.tintColor = [UIColor orangeColor];
}

- (void)changeSegment:(UISegmentedControl *)segment{
    NSLog(@"选中下标：%ld   选中标题：%@",segment.selectedSegmentIndex,[segment titleForSegmentAtIndex:segment.selectedSegmentIndex]);
    // 修改标题
    if (segment.selectedSegmentIndex == 1) {
        [segment setTitle:@"宝宝" forSegmentAtIndex:1];
    }else{
        [segment setTitle:@"?" forSegmentAtIndex:1];
    }
}

@end

运行效果：selectedSegmentIndex = 1