android - How to fix the position of one of the graphics when customizing a ViewGrounp with sliding events?

Question

I found that many ViewPager controls with indicators inherit a RelativeLayout and then disguise themselves as a ViewPager# through the proxy ViewPager method. ##, and indicator is overlaid on this ViewPager. I think this is a bit messy. I wanted to inherit a
ViewPager and then draw the indicator myself through canvas in onDraw, but I found that I was too young, indicatorWhen drawing, the layout is displayed on item 0 of ViwePager (it looks like it is on top of item 0), ViewPagerWhen slidingindicator also ran along.

As shown in the picture above, my

indicator followed. Then I let the x coordinates of my indicator be processed in onDraw using the ones obtained in getLocationOnScreen(). It turned out not to work.

In this case, the only thing I can think of is to wrap a layer of

RelativeLayout outside ViewPager like others, (of course I think FrameLayout is better)

But I am a little reluctant to deal with the control in this way. It cannot be solved with one

View but has to have three View nested in each other. I feel uncomfortable. Is there any way to make one ViewGounpWhile processing the sliding content in the control, is certain content not moved at the same time?

Before posting this question, I was thinking, should I monitor the offset of

ViewPager and then continuously move the content in the opposite direction in onDraw? I'll try it

Answer 1

I monitored onScrollChanged() to obtain the offset, and then added this offset in onDraw() to solve the problem.

But I found that the indicator in onDraw will be overwritten by the content in ViewPager~~ This solution still doesn’t work! ! Help