0

我想从camerroll异步获取所有图像现在我正在使用该代码，但我的应用程序被挂起，直到检索到所有图像，我注意到在instigram或其他应用程序中从camerroll加载图片不需要时间。

-(void)getAllPictures
{

    NSLog(@"i m in ");

    imageArray=[[NSArray alloc] init];
    mutableArray =[[NSMutableArray alloc]init];
    NSMutableArray* assetURLDictionaries = [[NSMutableArray alloc] init];
        library = [[ALAssetsLibrary alloc] init];
        void (^assetEnumerator)( ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {

            NSLog(@"i m in block");
        if(result != nil) {
            if([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {


                NSLog(@"result not nill");


                [assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];

                NSURL *url= (NSURL*) [[result defaultRepresentation]url];
                NSLog(@"url=%@",url);
                [library assetForURL:url
                         resultBlock:^(ALAsset *asset) {
                             [mutableArray addObject:[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]]];





                             imageArray=[[NSArray alloc] initWithArray:mutableArray];
                             [self allPhotosCollected:imageArray];


                             if ([mutableArray count]==count)
                             {NSLog(@"condition %lu , %i",(unsigned long)mutableArray.count,count);


                                 imageArray=[[NSArray alloc] initWithArray:mutableArray];
                                 [self allPhotosCollected:imageArray];
                             }
                         }
                        failureBlock:^(NSError *error){ NSLog(@"operation was not successfull!"); } ];

            }
        }
    };


    NSLog(@"image array= %@",imageArray);

    NSMutableArray *assetGroups = [[NSMutableArray alloc] init];

    void (^ assetGroupEnumerator) ( ALAssetsGroup *, BOOL *)= ^(ALAssetsGroup *group, BOOL *stop) {
        if(group != nil) {


            NSLog(@"group not nill");
            [group enumerateAssetsUsingBlock:assetEnumerator];
            [assetGroups addObject:group];
            count=(int)[group numberOfAssets];
        }
    };

    assetGroups = [[NSMutableArray alloc] init];

    [library enumerateGroupsWithTypes:ALAssetsGroupAll
                           usingBlock:assetGroupEnumerator
                         failureBlock:^(NSError *error) {NSLog(@"There is an error");}];
}

-(void)allPhotosCollected:(NSArray*)imgArray
{
    //write your code here after getting all the photos from library...
    NSLog(@"all pictures are %@",imgArray);
    [_collection_view reloadData];



   /*
    CGRect collectionFrame = self.collection_view.frame;

    collectionFrame.size.height=700;
    collectionFrame.size.width=320;*/

self.verticalLayoutConstraint.constant = 700;
    //self.collection_view.frame=collectionFrame;
}
4

2 回答 2

1

像这样尝试..它的速度越来越快。如果您将获取数组中的所有图像，那么它会在使用包含 1000 多张照片的 iPhone 和 iPad 时使您的应用程序崩溃。所以试试这样。

library = [[ALAssetsLibrary alloc] init];

if (library == nil)
    library = [[ALAssetsLibrary alloc] init];

[library enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop)
{

    [group enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop)
     {
         if (asset)
         {
             [imageArray addObject:asset];
             [collectionViewObj reloadData];
         }
     }];
 }
                failureBlock:^(NSError *error) 
{
    UIAlertView *alertViewObj = [[UIAlertView alloc]initWithTitle:@"Max6Miz does not have access to your photos" message:@"You can enable access in Settings" delegate:self cancelButtonTitle:nil otherButtonTitles:@"Settings",@"Ok", nil];
    [alertViewObj show];
    NSLog(@"error");
}];

使用此collectionView cellForItemAtIndexPath在您的委托函数中显示您的图像

ALAsset *asset = (ALAsset *)imageArray[indexPath.row];
UIImage *showingImage = [UIImage imageWithCGImage:[asset thumbnail]];
于 2015-09-09T06:36:45.120 回答
1

请使用Photos framework可从iOS 8.0. 我已经在存储在我自己的数百个相册中的 50k 照片和 1.5k 视频上对其进行了测试iCloud Photo Library。它运行速度很快，并允许跟踪和动画专辑和资产的变化。

这是一篇不错的文章Photos framework：https ://www.objc.io/issues/21-camera-and-photos/the-photos-framework/

于 2015-09-09T07:13:31.083 回答