Simple cropping with Paperclip

问题

I would like to crop images on upload using Paperclip to get square thumbs from the center of the original picture. I find out a method in documentation that seems to do exactly what I want:

transformation_to(dst, crop = false)

The problem is that I can't figure out where to use this method. It would be great to simply pass something as a parameter here:

  has_attached_file :picture, 
                    :styles => { :medium => "600x600>", :thumb => "something here" }

回答1:

You only need to use # instead of > as a parameter:

has_attached_file :picture, :styles => { :thumb => "200x200#" }

来源：https://stackoverflow.com/questions/1017509/simple-cropping-with-paperclip