将照片保存到相机胶卷并确保其实际保存

Question

我正在以这种方式将UIImage保存到相机胶卷。

UIImageWriteToSavedPhotosAlbum(finalPicture.image, nil, nil, nil);

但是，如果用户拒绝允许我们访问他们的照片会发生什么......我怎么能告诉，这已经发生了，显示错误消息？

Answer 1

要保存图像的相机胶卷我使用ALAssetsLibrary这样的方法：

//Called after taking the photo with the camera or selected the image from the gallery 
- (void)imagePickerController:(UIImagePickerController *) Picker didFinishPickingMediaWithInfo:(NSDictionary *)info { 

NSURL *referenceURL; 

if(Picker.sourceType==UIImagePickerControllerSourceTypeCamera){ 

    UIImage* takenImage=info[UIImagePickerControllerOriginalImage]; 

    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init]; 
    // Request to save the image to camera roll 
    [library writeImageToSavedPhotosAlbum:[takenImage CGImage] orientation:(ALAssetOrientation)[takenImage imageOrientation] completionBlock:^(NSURL *assetURL, NSError *error){ 
     if (error) { 
      //NOT SAVED 
      //DISPLAY ERROR THE PICTURE CAN'T BE SAVED 
     } else { 
      //SAVED 
     } 
    }];   

} 
}else{ 
//Selected from gallery 
} 

还记得，你必须先检查照相机。

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) 
    { 
     //The camera is available 
    }else{ 
     //No camera available 
    }