How to obtain the original file name of the image

问题:

I've implemented the delegate method and can get access to the picked UIImage, like this:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    UIImage *pickedImage = [info valueForKey:UIImagePickerControllerOriginalImage];

I want to save it to a directory, but I need a file name. So rather than just picking a random file name it would make sense to pick the same file name as the image.

Is there a way to retrieve it from that info dictionary?

回答1:

You could use the UIImagePickerControllerReferenceURL value of the info dictionary instead of the UIImagePickerControllerOriginalImage. This should give you the URL to the original media item.

This would return you a NSURL object which you then can use to build your new filename from.

回答2:

• Use ALA Assets library framework

• Use the code below

  
      ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
      UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
      [library writeImageToSavedPhotosAlbum:image.CGImage orientation:(ALAssetOrientation)image.imageOrientation completionBlock:^(NSURL *assetURL, NSError *error )
      {
         [library assetForURL:assetURL resultBlock:^(ALAsset *asset )
         {
           ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *imageAsset)
           {
               ALAssetRepresentation *imageRep = [imageAsset defaultRepresentation];
               NSLog(@"reference image filename picking from camera: %@", [imageRep filename]);
           };
           ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init];
           [assetslibrary assetForURL:assetURL resultBlock:resultblock failureBlock:nil];
         }
         failureBlock:^(NSError *error )
         {
             NSLog(@"Error loading asset");
         }];
      }];
  
  imageView.image = [info objectForKey:UIImagePickerControllerEditedImage];
  imageView.contentMode = UIViewContentModeScaleAspectFit;