android RelativeLayout change height programmatically

Question

I try change layout height programmatically. I have two buttons. In one button I change my layout position and second button I try to receive save position witch I was first time.

<RelativeLayout
    android:id="@+id/popaplayout"
    android:layout_width="fill_parent"
    android:layout_height="200dp" >

This is a my layout and in first button I wrote

RelativeLayout.LayoutParams parms = new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.FILL_PARENT,
                    RelativeLayout.LayoutParams.FILL_PARENT);
parms.addRule(RelativeLayout.BELOW, R.id.movies_title_layout);
scrollpopap.setLayoutParams(parms);
scrollpopap.setScrollingEnabled(true);

and second button

RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
                    ViewGroup.LayoutParams.WRAP_CONTENT, 300);
rel_btn.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
scrollpopap.setLayoutParams(rel_btn);
scrollpopap.setScrollingEnabled(false);

In xml file I wrote height 200dp and programmatically 300 and there are different height. How I can wrote save height in programmatically?

if anyone knows solution please help me thanks

Answer 1

First convert 200 dp into pixels -

final float scale = getContext().getResources().getDisplayMetrics().density;
int pixels = (int) (200 * scale + 0.5f);

Then set programatically,

RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
                    ViewGroup.LayoutParams.WRAP_CONTENT, pixels);
            rel_btn.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
            scrollpopap.setLayoutParams(rel_btn);
            scrollpopap.setScrollingEnabled(false);