添加UIImagePickerController时发出警告

Question

我正在尝试添加UIImagePickerController并收到incompatible type 'id<UINavigationControllerDelegate,UIImagePickerControllerDelegate>'编译器警告。我需要知道为什么？并为它提供解决方案。

的.m

imagePicker = [[UIImagePickerController alloc] init];
[imagePicker setDelegate:self];

·H

@interface GobblesViewController : UIViewController <UIImagePickerControllerDelegate>
{
  UIImagePickerController *imagePicker;
}
@property (nonatomic,strong)UIImagePickerController *imagePicker;

[imagePicker setDelegate:self];的警告点，我不知道为什么会发生这种情况。

Answer 1

您收到此警告是因为在这种情况下，您传递给self的{​​{1}}属性的对象UIImagePickerController不符合{ {1}} 和 delegate协议。这是因为UIImagePickerControllerDelegate是UINavigationControllerDelegate的子类，它已经声明了它自己的UIImagePickerController。

UINavigationController上的delegate属性定义为：

delegate

这意味着它预期任何符合这两个协议的对象。

您班级的UIImagePickerController声明应该是......

@property (nonatomic, assign) id <UINavigationControllerDelegate, UIImagePickerControllerDelegate> delegate;