55.UIbutton点击切换颜色

#import "ViewController.h"

#define width_w     [UIScreen mainScreen].bounds.size.width

#define height_h     [UIScreen mainScreen].bounds.size.height

#define PRO_W(width)  width_w*(width/320.0)

#define PRO_H(height)  height_h*(height/480.0)

@interface ViewController (){

    NSMutableArray *_titleArr;

    UIView *_view;

    UIButton *_btn2;

}

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.view.backgroundColor = [UIColor grayColor];

    _titleArr = [[NSMutableArray alloc]initWithObjects:@"上架时间",@"价格",@"销量",nil];

//    背景View

    _view = [[UIView alloc]initWithFrame:CGRectMake(0, 64, width_w, PRO_W(35))];

    _view.backgroundColor = [UIColor whiteColor];

    

    [self.view addSubview:_view];

    for (int i=0; i<_titleArr.count; i++) {

        

        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];

        btn.tag = i;

        [btn setTitle:[_titleArr objectAtIndex:i] forState:UIControlStateNormal];

        [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

        btn.titleLabel.font = [UIFont systemFontOfSize:13];

        btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

        btn.frame = CGRectMake((width_w/3)*i,0,width_w/3, PRO_W(35));

        [btn addTarget:self action:@selector(clickBtn:) forControlEvents:UIControlEventTouchUpInside];

        [_view addSubview:btn];

        UIView *lineView = [[UIView alloc]initWithFrame:CGRectMake((width_w/3)*i, PRO_W(5), 1,  PRO_W(25))];

        lineView.backgroundColor = [UIColor grayColor];

        [_view addSubview:lineView];

    }

}

-(void)clickBtn:(UIButton *)btn {

    if(_btn2== btn) {

//            //本次点击的按钮设为红色

             [btn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

    } else{

  

            //本次点击的按钮设为红色

            [btn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

            //将上次点击过的按钮设为黑色

            [_btn2 setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];

     }

    _btn2= btn;

}