I am able to get the pop up window but the background is transparent also I am able to read the contents of the activity behind it. I want to dim the background so the pop up and the older activity gets differentiated.
You can do it in 2 ways
1. by adding background color with transparency, to the parent of your popup layout.
example:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#cc000000">
<YOUR_POPUP_VIEW
.... />
</RelativeLayout>
WindowManager.LayoutParams layoutParams = getWindow().getAttributes();
layoutParams.dimAmount = #WHAT_EVER_VALUE_YOU_WANT_TO_KEEP; //Generally in between 0.70f to 0.80f
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
getWindow().setAttributes(layoutParams);