Question

I want to draw a straight vertical line in my Android activity when a button is pressed. Please explain how I can draw the line with a position & length I want.

Elaboration:
I have a linear layout with vertical orientation. A set of buttons constitute this linear layout. When I press one button, I want a line to appear to the right of these buttons, as if dividing the screen halfway – a straight line of width=2dip and height=200dip.

Answer 1

I have solved it myself.
All you need to do is define a View with appropriate parameters and fill the background with color. You may want to use nested linear layouts for positioning the line correctly.

<View 
      android:id="@+id/View01"
      android:layout_width="2dip"
      android:layout_height="500dip"
      android:background="#2B497B"
/>

So if it may be useful to anyone else, I have posted the answer here myself!