iOS UICollectionView 入門 07 點擊cell放大圖片
這一節,我們實現通過點擊圖片將圖片放大顯示的功能。
首先我們建立一個名為FlickrPhotoViewConroller的類,這個類繼承於UIViewController。修改標頭檔內容如下:
#import @class FlickrPhoto;@interface FlickrPhotoViewConroller : UIViewController@property (nonatomic, strong) FlickrPhoto *flickrPhoto;@end
聲明outlet和action:
#import "FlickrPhotoViewConroller.h"#import "Flickr.h"#import "FlickrPhoto.h"@interface FlickrPhotoViewConroller ()@property (weak) IBOutlet UIImageView *imageView;- (IBAction)done:(id)sender;@end
開啟storyboard,添加一個UIViewController到storyboard中,設定這個view的class為FlickrPhotoViewConroller。
從主view使用ctrl+drag建立一個到Flickr Photo view controller的modal segue。
選中這個segue,設定其identifier為ShowFlickrPhoto
添加一個toolbar和一個imageview到view中,修改toolbar按鈕標題為Done,ctrl+drag連線按鍵和FlickrPhotoViewController的done:方法。
再將imageView的outlet也串連上:
開啟ViewController.m,添加以下代碼到@interface地區中:
@property (nonatomic) BOOL sharing;
修改didSelectItemAtIndexPath方法:
if (!self.sharing) { NSString *searchTerm = self.searchs[indexPath.section]; FlickrPhoto *photo = self.searchResults[searchTerm][indexPath.row]; [self performSegueWithIdentifier:@"ShowFlickrPhoto" sender:photo]; [self.collectionView deselectItemAtIndexPath:indexPath animated:YES]; } else { }
當使用者點擊某幅縮圖時,執行ShowFlickrPhoto segue。
#import "FlickrPhotoViewConroller.h"- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{ if ([segue.identifier isEqualToString:@"ShowFlickrPhoto"]) { FlickrPhotoViewConroller *flickrPhotoViewController = segue.destinationViewController; flickrPhotoViewController.flickrPhoto = sender; }}
實現viewWillAppear方法,顯示大圖片到view中:
-(void)viewDidAppear:(BOOL)animated { // 1 if(self.flickrPhoto.largeImage) { self.imageView.image = self.flickrPhoto.largeImage; } else { // 2 self.imageView.image = self.flickrPhoto.thumbnail; // 3 [Flickr loadImageForPhoto:self.flickrPhoto thumbnail:NO completionBlock:^(UIImage *photoImage, NSError *error) { if(!error) { // 4 dispatch_async(dispatch_get_main_queue(), ^{ self.imageView.image = self.flickrPhoto.largeImage; }); } }]; }}
實現done方法,通過點擊Done按鈕返回到主view:
- (void)done:(id)sender{ [self.presentingViewController dismissViewControllerAnimated:YES completion:^{}];}
程式執行效果如下: