Question

How to set android:layout_alignParentBottom="true" for a videoview, by code and not from xml?

Answer 1

I assume you are trying to add your VideoView to a RelativeLayout ?

RelativeLayout relativeLayout = findViewById(R.id.your_relative_layout);
mVideo = new VideoView(this); 
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); // or wrap_content
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
relativeLayout.addView(mVideo , layoutParams);