从ALAssset检索时CGImage方向问题

Question

我刚开始学习iPhone应用程序开发.我正在尝试使用ALAsset类从我的相册中检索照片,并将照片上传到我的服务器.但是,在纵向模式下拍摄的照片向左旋转90度,同时正确上传风景照片.我究竟做错了什么？在NSLog中,我确实看到方向为3,但照片仍然向左旋转90度.任何帮助将不胜感激.

这是我的代码片段:

ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
{
   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
   NSString *documentsDirectory = [paths objectAtIndex:0];

   imagePath = [[documentsDirectory stringByAppendingPathComponent:@"latest_photo.jpg"] copy];
   NSLog(@"imagePath = %@", imagePath);

   ALAssetRepresentation *rep = [myasset defaultRepresentation];
   ALAssetOrientation orientation = [rep orientation];
   NSLog(@"Orientation = %d", orientation);

   CGImageRef iref = [rep fullResolutionImage];

   if (iref) {
      UIImage *largeimage = [UIImage imageWithCGImage:iref scale:1.0 orientation:orientation];
      NSData *webData = UIImageJPEGRepresentation(largeimage,0.5);

      [webData writeToFile:imagePath atomically:YES];

      // Upload the image

Answer 1

对于代码的资产定位部分,而不是

ALAssetRepresentation *rep = [myasset defaultRepresentation];
ALAssetOrientation orientation = [rep orientation];

尝试

ALAssetOrientation orientation = [[asset valueForProperty:@"ALAssetPropertyOrientation"] intValue];