How to programmatically set weight for Button

You can pass it in as part of the LinearLayout.LayoutParams constructor: Did you mean wrap_content?

LayoutParams param = new LinearLayout.LayoutParams(
                         LayoutParams.MATCH_PARENT,
                         LayoutParams.WRAP_CONTENT, 1.0f);

1.0f is the weight

LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
p.weight = 1;

rangeSeekBar.setLayoutParams(p);

I'm not sure which view you want to set the layout params on. I just assumed the rangeSeekbar to show an example. Change if you need.

When using the layout params always use the root's param type..

Ex. if you have a View you want to apply params to within a RelativeLayout use RelativeLayout.LayoutParams..