获取相册中最后保存的照片

Question

我使用AVFoundation框架拍照，并将其保存到相册：

- (void)captureStillImage
{  
    AVCaptureConnection *videoConnection = nil;
    for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
        for (AVCaptureInputPort *port in [connection inputPorts]) {
            if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
                videoConnection = connection;
                break;
            }
        }
        if (videoConnection) { 
      break; 
    }
    }if ([videoConnection isVideoOrientationSupported])
        [videoConnection setVideoOrientation:self.orientation];
    NSLog(@"about to request a capture from: %@", [self stillImageOutput]);
    [[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
                                                         completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error)
                                                           {
                                                               ALAssetsLibraryWriteImageCompletionBlock completionBlock = ^(NSURL *assetURL, NSError *error) {
                                                                   if (error) {
                                                                       NSLog(@"ERROR!!!");
                                                                   }
                                                               };
                                                               if (imageDataSampleBuffer != NULL)
                                                               {                                                                   
                                                                   NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
                                                                   ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
                                                                   UIImage *image = [[UIImage alloc] initWithData:imageData];
                                                                   [library writeImageToSavedPhotosAlbum:[image CGImage]
                                                                                             orientation:(ALAssetOrientation)[image imageOrientation]
                                                                                         completionBlock:completionBlock];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];
                                                               }
                                                           }];
}

I postNotification to the method saveImageToPhotoAlbum:

- (void)saveImageToPhotoAlbum
{   
    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
    // Enumerate just the photos and videos group by using ALAssetsGroupSavedPhotos.
    [library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
        // Within the group enumeration block, filter to enumerate just photos.
        [group setAssetsFilter:[ALAssetsFilter allPhotos]];
        // Chooses the photo at the last index
        [group enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:[group numberOfAssets] - 1] options:0 usingBlock:^(ALAsset *alAsset, NSUInteger index, BOOL *innerStop) {
            // The end of the enumeration is signaled by asset == nil.
            if (alAsset) {
                ALAssetRepresentation *representation = [alAsset defaultRepresentation];
                UIImage *latestPhoto = [UIImage imageWithCGImage:[representation fullScreenImage]];
                self.imageView.image = latestPhoto;
            }
        }];
    } failureBlock: ^(NSError *error) {
        NSLog(@"No groups");
    }];
  }

在那里，我使用了获取最后一张照片的代码，并将其显示在imageView上，但它显示的不是最后一张，而是前一张。所以如果我制作3张照片，它会显示2张，而不是3张。

有什么想法吗

谢谢你的帮助！

Answer 1

您的代码正在做它应该做的事情。您的代码逻辑有问题。您在保存图像之前发布通知。您必须在将图像写入库的完成块代码内发布通知。为什么不在imageView上显示捕获的图像，而不是从库中读取呢？？