Question

我知道很多时候可能会问这个问题，但我是一个初学者，所以温柔是一种谦虚的要求。

我正在尝试制作一个图片库，其中显示了网址的所有图片。

我已经使用了所有资产框架并制作了一个简单的图库，它返回了相机胶卷的图像，我想要一些URL的图像，所以请帮助我从网址获取图像并将其显示到图像库

这是视图控制器头文件

#import <UIKit/UIKit.h>
#import <AssetsLibrary/AssetsLibrary.h>

@interface ViewController : UIViewController <UICollectionViewDelegate,UICollectionViewDataSource>
@property (retain, nonatomic) IBOutlet UICollectionView *collectionView;
@property(nonatomic, strong) NSArray *assets;

这是实施文件，我在其中注册了一个.NIB文件，将Cell添加到我的CollectionView

#import "ViewController.h"
#import <AssetsLibrary/AssetsLibrary.h>
#import "MyCell.h"
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self.collectionView registerNib:[UINib nibWithNibName:@"MyCell" bundle:nil] forCellWithReuseIdentifier:@"CELL"];





_assets = [@[] mutableCopy];
__block NSMutableArray *tmpAssets = [@[] mutableCopy];
// 1

这里是calliing defaultAssetsLibrary方法，稍后您可以看到

 ALAssetsLibrary *assetsLibrary = [ViewController defaultAssetsLibrary];
    // 2
    [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
        [group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {


  if(result)
            {

                // 3
                [tmpAssets addObject:result];
            }
        }];

        // 4
        //NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"date" ascending:NO];
        //self.assets = [tmpAssets sortedArrayUsingDescriptors:@[sort]];
        self.assets = tmpAssets;

        // 5
        [self.collectionView reloadData];
    } failureBlock:^(NSError *error) {
        NSLog(@"Error loading images %@", error);
    }];



}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
#pragma mark - collection view data source


- (NSInteger) collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return self.assets.count;
}

// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:



- (MyCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    MyCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"CELL" forIndexPath:indexPath];

    ALAsset *asset = self.assets[indexPath.row];
    cell.asset = asset;
    cell.backgroundColor = [UIColor redColor];
    ////
    //=


    cell.cellLabel.text = [NSString stringWithFormat:@"cell %i",indexPath.row];
    return cell;
}

- (void) collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    ALAsset *asset = self.assets[indexPath.row];
    ALAssetRepresentation *defaultRep = [asset defaultRepresentation];
    UIImage *image = [UIImage imageWithCGImage:[defaultRep fullScreenImage] scale:[defaultRep scale] orientation:0];

    // Do something with the image

}

这是我认为返回照片库的方法

+ (ALAssetsLibrary *)defaultAssetsLibrary
{


    static dispatch_once_t pred = 0;
    static ALAssetsLibrary *library = nil;
    dispatch_once(&pred, ^{
        library = [[ALAssetsLibrary alloc] init];
    });
    return library;
}

请帮我从URL获取图片并在图片库中显示。

只要关注MyCell文件。

这是MYCell.m文件

@interface MyCell ()
// 1
@property(nonatomic, strong) IBOutlet UIImageView *photoImageView;
@end

@implementation MyCell

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void) setAsset:(ALAsset *)asset
{


    // 2
    _asset = asset;
    self.photoImageView.image = [UIImage imageWithCGImage:[asset thumbnail]];
    }

Answer 1

如果我们从网址获取图片，我们真的不需要AlAsset图片库。

我已经按照本教程制作了图片库Guide，并且Simple传递了url数组，它对我有用。

从URL获取图像并将其显示到图像库AlAsset

1 个答案: