testALAssetsLibrary

• iOS開發(fā)中有時候會經(jīng)常需要拍照和選取圖片疾就，拍照直接調(diào)用UIImageViewPicker就可以了，如若要自定義相機(jī)的話可以自己定義拍照頁面做葵，此先略過不講坑鱼。這篇文章只講述如何自定義相冊——利用系統(tǒng)的<AssetsLibrary/AssetsLibrary.h>框架。
• 首先第一步呼股，當(dāng)然是要導(dǎo)入<AssetsLibrary/AssetsLibrary.h>框架

導(dǎo)入框架

#import <AssetsLibrary/AssetsLibrary.h>
#import <AssetsLibrary/ALAsset.h>
#import <AssetsLibrary/ALAssetsLibrary.h>
#import <AssetsLibrary/ALAssetsGroup.h>
#import <AssetsLibrary/ALAssetRepresentation.h>

循環(huán)遍歷ALAssetsLibrary彭谁，調(diào)用enumerateGroupsWithTypes的block马靠。

    [_assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
    if (group)
    {
        //NSLog(@"*****相冊個數(shù)***%@",self.groupMutArr);
        [self.groupMutArr addObject:group];
        //每個相冊的名字
        NSString *groupName = [group valueForProperty:ALAssetsGroupPropertyName];
        [self.groupName addObject:groupName];
        
        for (ALAssetsGroup *_group in self.groupMutArr)
        {
            [_group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
                if (result)
                {
                    [self.imageArr addObject:result];
                    //NSLog(@"*****所有相冊里的所有圖片****%@",self.imageArr);
                    //UIImage *image = [UIImage imageWithCGImage: result.thumbnail];
                    //NSString *type=[result valueForProperty:ALAssetPropertyType];
                }
            }];
        }
    }
    
    [self.collectionView reloadData];
    
    } failureBlock:^(NSError *error) {
    NSLog(@"獲取相冊失敗");
    }];

根據(jù)數(shù)據(jù)數(shù)組來定義collectionView逞度，返回?cái)?shù)組

    pragma mark - UICollectionViewDataSource
    - (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
    {
        NSMutableArray *testMutArr = [NSMutableArray array];
        ALAssetsGroup *testGroup = [self.groupMutArr objectAtIndex:section];
        [testGroup enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
            if (result)
            {
                [testMutArr addObject:result];
            }
        }];
        
        return testMutArr.count;
    }
    
    - (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
    {
        return self.groupMutArr.count;
    }
    
    - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
    {
        YBTNFirstCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:TNFirstCell forIndexPath:indexPath];
        
        NSMutableArray *mutArr = [NSMutableArray array];
        ALAssetsGroup *testGroup = [self.groupMutArr objectAtIndex:indexPath.section];
        [testGroup enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
            if (result){
                [mutArr addObject:result];
            }}];
        
        ALAsset *result = [mutArr objectAtIndex:indexPath.item];
        UIImage *image = [UIImage imageWithCGImage: result.thumbnail];
        [cell setCellWithImage:image];
        return cell;
    }

項(xiàng)目截圖如下：

截圖

參考在此項(xiàng)目demo