问题
Check out this jsbin
I want my images have auto height with sizing="contain", it means they won't have extra space. In my example those extra space are in red.
iron image is required to set a fixed height otherwise image not display, I tried height:auto and height:100% but not work.
回答1:
I was using paper-material, should use paper-card
来源：https://stackoverflow.com/questions/32398417/how-to-give-polymer-iron-image-auto-height