圖片選擇器，看cocoachina發現一個有趣的框架，很好用，分享一下，其實做出該功能我之前寫過一篇部落格，使用轉場動畫寫的，就是圖片的手勢縮放沒寫，有興趣可以看看

效果圖：

github地址：https://github.com/coder-zwz/MJPhotoBrowser

使用：

#import "ViewController.h"
#import "MJPhotoBrowser.h"
@interface ViewController ()
{
    NSArray *_urls;
}
@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor groupTableViewBackgroundColor];
    // 0.圖片連結
    _urls = @[@"http://ww4.sinaimg.cn/thumbnail/7f8c1087gw1e9g06pc68ug20ag05y4qq.gif", @"http://ww3.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr0nly5j20pf0gygo6.jpg", @"http://ww4.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr1d0vyj20pf0gytcj.jpg", @"http://ww3.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr1xydcj20gy0o9q6s.jpg", @"http://ww2.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr2n1jjj20gy0o9tcc.jpg", @"http://ww2.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr39ht9j20gy0o6q74.jpg", @"http://ww3.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr3xvtlj20gy0obadv.jpg", @"http://ww4.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr4nndfj20gy0o9q6i.jpg", @"http://ww3.sinaimg.cn/thumbnail/8e88b0c1gw1e9lpr57tn9j20gy0obn0f.jpg"];
    
    // 1.建立9個UIImageView
    UIImage *placeholder = [UIImage imageNamed:@"timeline_image_loading.png"];
    CGFloat width = 80;
    CGFloat height = 80;
    CGFloat margin = 5;
    CGFloat startX = (self.view.frame.size.width - 3 * width - 2 * margin) * 0.5;
    CGFloat startY = 80;
    for (int i = 0; i<9; i++) {
        UIImageView *imageView = [[UIImageView alloc] init];
        [self.view addSubview:imageView];
        
        // 計算位置
        int row = i/3;
        int column = i%3;
        CGFloat x = startX + column * (width + margin);
        CGFloat y = startY + row * (height + margin);
        imageView.frame = CGRectMake(x, y, width, height);
        
        // 下載圖片
        [imageView setImageURLStr:_urls[i] placeholder:placeholder];
        
        // 事件監聽
        imageView.tag = i;
        imageView.userInteractionEnabled = YES;
        [imageView addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapImage:)]];
        
        // 內容模式
        imageView.clipsToBounds = YES;
        imageView.contentMode = UIViewContentModeScaleAspectFill;
    }
}

- (void)tapImage:(UITapGestureRecognizer *)tap
{
    NSInteger count = _urls.count;
    // 1.封裝圖片資料
    NSMutableArray *photos = [NSMutableArray arrayWithCapacity:count];
    for (int i = 0; i<count; i++) {
        // 替換為中等尺寸圖片
        NSString *url = [_urls[i] stringByReplacingOccurrencesOfString:@"thumbnail" withString:@"bmiddle"];
        MJPhoto *photo = [[MJPhoto alloc] init];
        photo.url = [NSURL URLWithString:url]; // 圖片路徑
        photo.srcImageView = self.view.subviews[i]; // 來源於哪個UIImageView
        [photos addObject:photo];
    }
    
    // 2.顯示相簿
    MJPhotoBrowser *browser = [[MJPhotoBrowser alloc] init];
    browser.currentPhotoIndex = tap.view.tag; // 彈出相簿時顯示的第一張圖片是？
    browser.photos = photos; // 設定所有的圖片
    [browser show];
}


@end