警告添加UIImagePickerController

Question

我试图添加一个UIImagePickerController，我得到一个incompatible type 'id<UINavigationControllerDelegate,UIImagePickerControllerDelegate>'编译器警告。我需要知道为什么？并为其提供解决方案。

.M

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

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

警告点[imagePicker setDelegate:self];，我不知道这是为什么发生的.h。

Answer 1

你得到这个警告，因为对象，self在这种情况下，你传递到UIImagePickerController的delegate财产，不符合UIImagePickerControllerDelegate和UINavigationControllerDelegate协议。这是因为UIImagePickerController是UINavigationController的一个子类，它已经声明它自己的delegate。

UIImagePickerController上的delegate属性被定义为：

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

这意味着它是预期符合这两个协议的任何对象。

的@interface声明你的类应该是...

@interface GobblesViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>