r - How to create a continous legend in ggplot2 as a separate object

Question

I am currently working with ggplot2 to arrange several ggplot2 object together, and I would like to make legend seperately and attached them to the final figure.

I wonder how to make a continoues bar legend to show a range of 0-1 (break at 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1) as a ggplot object?

Thanks.

Answer 1

等待大神解答