android - how to change textview's text dynamically when swiping the view pager? -

i having textview above viewpager. want change text of textview while swiping view pager.

below needed in case:

viewpager page1 ----> textview's text text1

viewpager page2 ----> textview's text text2

viewpager page3 ----> textview's text text3

viewpager page4 ----> textview's text text4

when swiping back

viewpager page4 ----> textview's text text4

viewpager page3 ----> textview's text text3

viewpager page2 ----> textview's text text2

viewpager page1 ----> textview's text text1

currently setting text of textview in below method:

        @override     public charsequence getpagetitle(int position) {          switch (position) {         case 0:             mytextview.settext(text1);             return "title1";         case 1:             mytextview.settext(text2);             return "title2";         case 2:             mytextview.settext(text3);             return "title3";         case 3:             mytextview.settext(text4);             return "title4";         }         return null;     } 

using method able set text of mytextview page 2,3,4. page1 not able set text shown in above method. instead setting page2' textview text.

why happening? , give solution problem. should set textview's text(view above view pager) when using view pager.

try viewpager.setonpagechangelistener();

you can find documentation here