4

我试图从照片库中检索图像并使用 AssetsLibrary 在我的应用程序中显示。我得到了照片的 URL 路径，但我不知道如何通过它获取照片。

我的代码如下：

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


   void (^assetEnumerator)( ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
       if(result != nil) {
           if([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {
                [assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];

                NSLog(@"result is:%@",result);
                NSLog(@"asset URLDictionary is:%@",assetURLDictionaries);
                NSURL *url= (NSURL*) [[result defaultRepresentation]url]; 

                [library assetForURL:url
                         resultBlock:^(ALAsset *asset) { [assetsp addObject:asset]; }
                        failureBlock:^(NSError *error){ NSLog(@"test:Fail"); } ]; 
           } 
       }
   };


   NSMutableArray *assetGroups = [[NSMutableArray alloc] init];
   void (^ assetGroupEnumerator) ( ALAssetsGroup *, BOOL *)= ^(ALAssetsGroup *group, BOOL *stop){
        NSLog(@"hi");
        if(group != nil) {
            [group enumerateAssetsUsingBlock:assetEnumerator];
            [assetGroups addObject:group];

            NSLog(@"Number of assets in group :%d",[group numberOfAssets]);           
        }
   };

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

   [library enumerateGroupsWithTypes:ALAssetsGroupAll
                          usingBlock:assetGroupEnumerator
                        failureBlock:^(NSError *error) {NSLog(@"A problem occurred");}];
4

2 回答 2

3

我的代码如下：

- (void)viewDidLoad
{
    carousel.type = iCarouselTypeCoverFlow2;
    [super viewDidLoad];
    xy =[[NSMutableArray alloc]init];

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

    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

    void (^assetEnumerator)( ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
        if(result != nil) {
            if([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {
                [assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];

                NSLog(@"result is:%@",result);
                NSLog(@"asset URLDictionary is:%@",assetURLDictionaries);
                NSURL *url= (NSURL*) [[result defaultRepresentation]url]; 

                [library assetForURL:url
                         resultBlock:^(ALAsset *asset) {
                             [xy addObject:[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]]];
                             NSLog(@" xy is:%@",xy);
                             image =[ [UIImageView alloc ] initWithImage:[xy objectAtIndex:0]];
                             NSLog(@"image is:%@",image);
                         }
                         failureBlock:^(NSError *error){ NSLog(@"test:Fail"); } ]; 
            } 
        }
    };

    NSMutableArray *assetGroups = [[NSMutableArray alloc] init];
    void (^ assetGroupEnumerator) ( ALAssetsGroup *, BOOL *)= ^(ALAssetsGroup *group, BOOL *stop) {
        NSLog(@"hello");
        if(group != nil) {
            [group enumerateAssetsUsingBlock:assetEnumerator];
            [assetGroups addObject:group];
            NSLog(@"Number of assets in group :%d",[group numberOfAssets]);
            NSLog(@"asset group is:%@",assetGroups);
        }
    };

    assetGroups = [[NSMutableArray alloc] init];

    [library enumerateGroupsWithTypes:ALAssetsGroupAll
             usingBlock:assetGroupEnumerator
             failureBlock:^(NSError *error) {NSLog(@"A problem occurred");}];
于 2012-07-17T06:36:41.930 回答
3

这段代码是从这里的一些 ELCImagePickerController 示例中获取的 。为了简化，做了一些修改。

愿这对你有帮助

[self.assetGroup enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) 
     {         
         if(result == nil) 
             return;
         UIImageView *assetImageView = [[UIImageView alloc] initWithFrame:viewFrames];
        [assetImageView setContentMode:UIViewContentModeScaleToFill];
        [assetImageView setImage:[UIImage imageWithCGImage:[result thumbnail]]];
     }];

快乐编码:)

新答案

只需使用

[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]]

直接存储图像，而不是在存储资产时存储资产assetsp

如下

void (^assetEnumerator)( ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
       if(result != nil) {
           if([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {
                [assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];

                NSLog(@"result is:%@",result);
                NSLog(@"asset URLDictionary is:%@",assetURLDictionaries);
                NSURL *url= (NSURL*) [[result defaultRepresentation]url]; 

                [library assetForURL:url
                         resultBlock:^(ALAsset *asset) { //Your line
                                                           //[assetsp addObject:asset];
                                                         //My Changed line will store image directly to assetsp
                                                           [assetsp addObject:[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]]];
                                                       }
                        failureBlock:^(NSError *error){ NSLog(@"test:Fail"); } ]; 
           } 
       }
   };

新答案 1

尝试使用此代码将 ALAsset 数据存储在可变数组中

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

    for(ALAsset *asset in _assets) {

        NSMutableDictionary *workingDictionary = [[NSMutableDictionary alloc] init];
        [workingDictionary setObject:[asset valueForProperty:ALAssetPropertyType] forKey:@"UIImagePickerControllerMediaType"];
        [workingDictionary setObject:[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]] forKey:@"UIImagePickerControllerOriginalImage"];
        [workingDictionary setObject:[[asset valueForProperty:ALAssetPropertyURLs] valueForKey:[[[asset valueForProperty:ALAssetPropertyURLs] allKeys] objectAtIndex:0]] forKey:@"UIImagePickerControllerReferenceURL"];

        [returnArray addObject:workingDictionary];

并在 UIImageView 中获取图像只需执行此操作

NSDictionary *dict = [info objectAtIndex:i];
        UIImageView *imageview = [[UIImageView alloc] initWithImage:[dict objectForKey:UIImagePickerControllerOriginalImage]];
        [imageview setContentMode:UIViewContentModeScaleAspectFit];
于 2012-07-07T11:31:59.827 回答