如何从iphone photoLibrary中获取照片总数？

Question

我想要获取photoLibrary中的照片数量。目前，我可以从photoLibrary获取照片，并逐一添加到我的应用程序的文档目录中。但我想要的是，保存所有的照片从photoLibrary到文件目录的myApp所有的一次。这就是为什么我需要在photoLibrary中计算照片的数量。我已经使用UIImagePickerControllerSourceTypePhotoLibrary从iPhone photoLibrary检索了照片。

任何帮助都将受到欢迎..

提前感谢....

Answer 1

使用ALAssetsLibrary执行以下操作：

 int imgCount = 0;
 self.assetsLibrary = [[ALAssetsLibrary alloc] init];
 dispatch_queue_t dispatchQueue =  dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
 dispatch_async(dispatchQueue, ^(void) {
 [self.assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
 [group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index,
  __block BOOL foundThePhoto = NO;
 if (foundThePhoto){ *stop = YES;
 }
 BOOL *stop) {
 /* Get the asset type */ 
 NSString *assetType = [result valueForProperty:ALAssetPropertyType];
 if ([assetType isEqualToString:ALAssetTypePhoto]){ NSLog(@"This is a photo asset");
 foundThePhoto = YES; *stop = YES;
 /* Get the asset's representation object */ 
 ALAssetRepresentation *assetRepresentation = [result defaultRepresentation];
 /* We need the scale and orientation to be able to construct a properly oriented and scaled UIImage out of the representation object */
 CGFloat imageScale = [assetRepresentation scale];
 UIImageOrientation imageOrientation = (UIImageOrientation)[assetRepresentation orientation];
 dispatch_async(dispatch_get_main_queue(), ^(void) {
 CGImageRef imageReference = [assetRepresentation fullResolutionImage];
 /* Construct the image now */ 
 UIImage    *image = [[UIImage alloc]   initWithCGImage:imageReference
 scale:imageScale orientation:imageOrientation];
 //Write image to doument directory 
 imgCount ++;
 }
 });
 } failureBlock:^(NSError *error) {
 } }];
 NSLog(@"Failed to enumerate the asset groups."); }];
 })

 NSLog(@"Total Image Count %d",imgCount);

Answer 2

下面的代码块统计所有的视频和照片：

__block int videoCount = 0;
__block int photoCount = 0;
ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc]init];
[assetLibrary
 enumerateGroupsWithTypes:ALAssetsGroupAll
 usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
     if (group == nil) {
         // enumeration complete
         return;
     }
     int total = group.numberOfAssets;
     [group setAssetsFilter:[ALAssetsFilter allVideos]];
     int groupVideoCount = group.numberOfAssets;
     videoCount += groupVideoCount;
     photoCount += total - groupVideoCount;
 }
 failureBlock:^(NSError *error) {
     // Handle error
 }];