相关疑难解决方法(0)

我正在解雇模态视图控制器然后立即呈现另一个,但后者永远不会发生.这是代码:

 [self dismissModalViewControllerAnimated:YES];

 UIImagePickerController *picker = [[UIImagePickerController alloc] init];
 picker.delegate = self;
 picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
 [self presentModalViewController:picker animated:YES];

第一个模态VC向下滑动,但新的picker永远不会出现.知道发生了什么事吗？