iphone - 检查 UIImage 属性是否被分配？

Question

我有一个UIImage属性，从 iPhone 相机拍摄图像后，我将图像对象分配给该属性，否则没有。拍摄后如何检查此属性是否包含图像？下面我的代码没有帮助。

@interface MyViewController : UIView<UINavigationControllerDelegate, UIImagePickerControllerDelegate>
@property(nonatomic, retain) UIImage *imageShot;
@end

@implementation MyViewController
@synthesize imageShot = _imageShot;

- (id)init {
    self = [super init];
    if (self) {
        _imageShot = [[UiImage alloc] init];
    }
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    self.imageShot = [info objectForKey:UIImagePickerControllerEditedImage];
}

- (void)buttonClick {
    if (_imageShot) {

    } 
    else {

    }
}

@end

Answer 1

在您的init中，您应该创建shotedImage而nil不是分配一个新的空图像。这将允许执行像if (!shotedImage)(as nil == 0) 这样的测试。