图片浏览器

我们在网上浏览新闻或者用手机移动设备会常常 使用图片浏览器 

图片浏览器 就是能够让用户选择 进行上翻下翻浏览图片信息

当图片浏览到最后一张的时候，那么箭头会变成灰色 不能再进行点击

假设图片浏览在第一张。我们也不能再进行点击 

那么我们进行一下简单的分析实现

#import "ViewController.h"

@interface ViewController ()
- (IBAction)previous;
- (IBAction)next;
@property (weak, nonatomic) IBOutlet UIButton *preBtn;
@property (weak, nonatomic) IBOutlet UIButton *nextBtn;


@property (weak, nonatomic) IBOutlet UILabel *noLabel;
@property (weak, nonatomic) IBOutlet UIImageView *iconView;
@property (weak, nonatomic) IBOutlet UILabel *descLabel;
//记录当前显示的是第几张图片
@property(nonatomic,assign)int index;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.index = -1;
    [self next];
    /*
    //1、设置索引
    self.noLabel.text = @"1/5";
    //2.图片
    self.iconView.image = [UIImage imageNamed:@"biaoqingdi"];
    //3.描写叙述
    self.descLabel.text = @"哈哈";
    
    self.preBtn.enabled = NO;
     */
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark 切换图片
-(void)changeData
{
    self.preBtn.enabled = (self.index!=0);
    self.nextBtn.enabled = (self.index!=4);
    
    switch (self.index) {
        case 0:
            self.noLabel.text = @"1/5";
            self.iconView.image = [UIImage imageNamed:@"biaoqingdi"];
            self.descLabel.text=@"表情";
            break;
            
        case 1:
            self.noLabel.text = @"2/5";
            self.iconView.image = [UIImage imageNamed:@"wangba"];
            self.descLabel.text = @"八号";
            break;
        case 2:
            self.noLabel.text = @"3/5";
            self.iconView.image = [UIImage imageNamed:@"bingli"];
            self.descLabel.text = @"这也忒严重了";
            break;
        case 3:
            self.noLabel.text = @"4/5";
            self.iconView.image = [UIImage imageNamed:@"chiniupa"];
            self.descLabel.text = @"这样子。。
。";
            break;
        case 4:
            self.noLabel.text = @"5/5";
            self.iconView.image = [UIImage imageNamed:@"danteng"];
            self.descLabel.text = @"能不能换个网名";
            break;
            
            
        default:
            break;
    }

}
#pragma mark 上一张
- (IBAction)previous {
    self.index--;
    [self changeData];
    
//    self.preBtn.enabled = (self.index!=0);
//    self.nextBtn.enabled = (self.index!=4);
    /*
    if (self.index==0) {
        self.preBtn.enabled = NO;
    }
    else
        self.preBtn.enabled = YES;
    if (self.index == 4) {
        self.nextBtn.enabled = NO;
    }
    else
        self.nextBtn.enabled = YES;
     */
    /*
    switch (self.index) {
        case 0:
            self.noLabel.text = @"1/5";
            self.iconView.image = [UIImage imageNamed:@"biaoqingdi"];
            self.descLabel.text=@"表情";
            break;
            
        case 1:
            self.noLabel.text = @"2/5";
            self.iconView.image = [UIImage imageNamed:@"wangba"];
            self.descLabel.text = @"八号";
            break;
        case 2:
            self.noLabel.text = @"3/5";
            self.iconView.image = [UIImage imageNamed:@"bingli"];
            self.descLabel.text = @"严重了";
            break;
        case 3:
            self.noLabel.text = @"4/5";
            self.iconView.image = [UIImage imageNamed:@"chiniupa"];
            self.descLabel.text = @"这样子。
。
。
";
            break;
        case 4:
            self.noLabel.text = @"5/5";
            self.iconView.image = [UIImage imageNamed:@"danteng"];
            self.descLabel.text = @"能不能换个网名";
            break;
            
            
        default:
            break;
    }
     */
    //self.index = self.index -1;
}

#pragma mark 下一张
- (IBAction)next {
    self.index++;
    [self changeData];
    
    /*
    switch (self.index) {
        case 0:
            self.noLabel.text = @"1/5";
            self.iconView.image = [UIImage imageNamed:@"biaoqingdi"];
            self.descLabel.text=@"表情帝";
            break;
            
        case 1:
            self.noLabel.text = @"2/5";
            self.iconView.image = [UIImage imageNamed:@"wangba"];
            self.descLabel.text = @"选八号";
            break;
        case 2:
            self.noLabel.text = @"3/5";
            self.iconView.image = [UIImage imageNamed:@"bingli"];
            self.descLabel.text = @"严重了";
            break;
        case 3:
            self.noLabel.text = @"4/5";
            self.iconView.image = [UIImage imageNamed:@"chiniupa"];
            self.descLabel.text = @"这样子。。。";
            break;
        case 4:
            self.noLabel.text = @"5/5";
            self.iconView.image = [UIImage imageNamed:@"danteng"];
            self.descLabel.text = @"能不能换个网名";
            break;
            
            
        default:
            break;
    }
     */

    
}
@end