如何以编程方式或强制方式调用UIImagePickerController委托[无需用户交互]？

1 回答

• 2

  委托方法的想法并不是你称这些方法 - “他们叫你” .

  所以我不认为自己调用委托方法是一个好习惯 . 但是，如果你给 UIImagePickerViewController 提供一个模态对话（我猜这种选择器很常见），那么你可以在你的委托方法之外关闭它：

  [[yourPicker parentViewController] dismissModalViewControllerAnimated:YES];
  

  Source

  Update: 您可以使用ALAssetsLibrary访问iPhone媒体库中存储的数据 . 我最近不得不做一个类似的项目，我必须列出iPhone上的所有图像 . Github项目ELCImagePickerController.git非常有用，因为它显示了如何访问库中的项目 . 所以你会做这样的事情：

  #import <AssetsLibrary/AssetsLibrary.h>
  
  // ....
  
  -(void)fetchPhotoAlbums{
  
      if(!self.assetsGroups){
          self.assetsGroups = [NSMutableDictionary dictionary];
      }
  
      ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];      
      NSMutableArray *returnArray = [[NSMutableArray alloc] init];
  
          @autoreleasepool {
              void (^assetGroupEnumerator)(ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop){
                  if (group == nil){
                     // Completed
                     [self.delegate pictureService:self fetchedAlbums:returnArray]; 
                      return;
                  }
  
                  Album *currentAlbum = [self albumForAssetsGroup:group];
  
                  // Store the Group for later retrieving the pictures for the album
                  [self.assetsGroups setObject:group forKey:currentAlbum.identifier];
                  [returnArray addObject:currentAlbum];
                  [self.delegate pictureService:self fetchedAlbums:returnArray];
               };
  
              void (^assetGroupEnumberatorFailure)(NSError *) = ^(NSError *error) {
                  NSLog(@"A problem occured %@", [error description]);                                     
              };  
  
              [library enumerateGroupsWithTypes:ALAssetsGroupAll
                                     usingBlock:assetGroupEnumerator 
                                   failureBlock:assetGroupEnumberatorFailure];   
          }
  }
  
  
  -(void)fetchPhotosForAlbum:(Album *)album{
  
      ALAssetsGroup *currentGroup = [self.assetsGroups objectForKey:album.identifier];
      NSMutableArray *photos = [NSMutableArray array];
      [currentGroup enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop){         
           if(asset == nil){
               [self.delegate pictureService:self fetchedPictures:photos forAlbum:album];
               return;
           }
  
           [photos addObject:[self pictureForAsset:asset]];
       }];
  }
  

  另外，我使用两个映射器方法将AL类转换为我自己的模型类 .

  - (Album *)albumForAssetsGroup:(ALAssetsGroup *)assetsGroup{
      Album *album = [[Album alloc] init];
      album.title = [assetsGroup valueForProperty:ALAssetsGroupPropertyName];
      album.identifier = [assetsGroup valueForProperty: ALAssetsGroupPropertyPersistentID];
      album.assetsCount = assetsGroup.numberOfAssets;
      album.thumbnail = [UIImage imageWithCGImage:assetsGroup.posterImage];
      return album;
  }
  
  - (Picture *)pictureForAsset:(ALAsset *)asset{
      Picture *picture = [[Picture alloc]init];
      picture.identifier = [((NSArray *)[asset valueForProperty: ALAssetPropertyRepresentations]) objectAtIndex:0];
      picture.thumbnail = [UIImage imageWithCGImage:asset.thumbnail];
      return picture;
  }
  

  见AssetsLibrary Documentation

  回复于 2024-05-02T11:03:54+08:00