AVCamDemo：未单击完成处理程序代码

captureStillImage()

- (void) captureStillImage
{
    AVCaptureConnection *stillImageConnection = [AVCamUtilities connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self stillImageOutput] connections]];
    if ([stillImageConnection isVideoOrientationSupported]) {
        [stillImageConnection setVideoOrientation:orientation];
    }
    [[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:stillImageConnection
                completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
NSLog(@\"In the completionHandler block\");
           if (imageDataSampleBuffer != NULL) {
               NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
               UIImage *image = [[UIImage alloc] initWithData:imageData];
                     [self writeImageFile:image];
                     [image release];
            }
          if ([[self delegate] respondsToSelector:@selector(captureManagerStillImageCaptured:)]) {
               [[self delegate] captureManagerStillImageCaptured:self];
                }
     }];
NSLog(@\"exiting....\");
}