警告添加UIImagePickerController

Question

我試圖添加一個UIImagePickerController，我得到一個incompatible type 'id<UINavigationControllerDelegate,UIImagePickerControllerDelegate>'編譯器警告。我需要知道爲什麼？併爲其提供解決方案。

.M

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

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

警告點[imagePicker setDelegate:self];，我不知道這是爲什麼發生的.h。

Answer 1

你得到這個警告，因爲對象，self在這種情況下，你傳遞到UIImagePickerController的delegate財產，不符合UIImagePickerControllerDelegate和UINavigationControllerDelegate協議。這是因爲UIImagePickerController是UINavigationController的一個子類，它已經聲明它自己的delegate。

UIImagePickerController上的delegate屬性被定義爲：

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

這意味着它是預期符合這兩個協議的任何對象。

的@interface聲明你的類應該是...

@interface GobblesViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>