Android SeekBar - How to make smaller at right and bigger at left

I want SeekBar as follow:

- Slide to the r开发者_开发百科ight: value is decreased: exp, from 255 down to 0

- Slide to the left: value is increased: exp, from 0 up to 255

Or, if SeekBar cannt do something like that, what component should I use?

Please give me advice!

Thanks very much!

It's simply. Take a SeekBar, set it from 0 to 255, and on change calculate the output value based on SeekBar's progress the way you like.