我有一个应用程序,我在其中用相机拍照并将该图像存储到本机图库中。但是,如果应用程序没有权限,我希望用户知道这一点。那么我该如何检查呢?
顺便说一句:我将图像存储到图库中:
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
您需要检查状态ALAssetLibrary 
以确保您已AssetsLibrary/AssetsLibrary.h包含在文件中
  ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];
// 检查ALAuthorizationStatusAuthorizedor的状态,ALAuthorizationStatusDenied例如
    if (status != ALAuthorizationStatusAuthorized) {
        //show alert for asking the user to give permission
    }
斯威夫特 3
import photos
PHPhotoLibrary.requestAuthorization { status in
     switch status {
     case .authorized:
          self.processSnapShotPhotos()
     case .restricted:
          print("handle restricted")
     case .denied:
          print("handle denied")     
     default:
       // place for .notDetermined - in this callback status is already determined so should never get here
            break
     }
}
如果您正在使用照片框架,因为 ALAsset 库已从 ios 9 中弃用,您可以使用 PHAuthorizationStatus 检查图库访问权限。您还需要导入照片框架。
  #import <Photos/Photos.h>
- (BOOL)hasGalleryPermission
{
    BOOL hasGalleryPermission = NO;
    PHAuthorizationStatus authorizationStatus = [PHPhotoLibrary authorizationStatus];
    if (authorizationStatus == PHAuthorizationStatusAuthorized) {
        hasGalleryPermission = YES;
    }
    return hasGalleryPermission;
}
注意:仅限 iOS 6
这是你想要的
[ALAssetsLibrary authorizationStatus] == ALAuthorizationStatusAuthorized;
authorizationStatus 的其他值是
ALAuthorizationStatusRestricted,        // This application is not authorized to access photo data.
                                            // The user cannot change this application’s status, possibly due to active restrictions
                                            //  such as parental controls being in place.
    ALAuthorizationStatusDenied,            // User has explicitly denied this application access to photos data.
    ALAuthorizationStatusAuthorized         // User has authorized this application to access photos data.