How to scroll to top of long ScrollView layout?

Try

mainScrollView.fullScroll(ScrollView.FOCUS_UP);

it should work.

Had the same issue, probably some kind of bug.

Even the fullScroll(ScrollView.FOCUS_UP) from the other answer didn't work.
Only thing that worked for me was calling scroll_view.smoothScrollTo(0,0) right after the dialog is shown.

i had the same problem and this fixed it. Hope it helps you.

listView.setFocusable(false);

scrollViewObject.fullScroll(ScrollView.FOCUS_UP) this works fine, but only the problem with this line is that, when data is populating in scrollViewObject, has been called immediately. You have to wait for some milliseconds until data is populated. Try this code:

scrollViewObject.postDelayed(new Runnable() {
    @Override
    public void run() {
        scroll.fullScroll(ScrollView.FOCUS_UP);
    }
}, 600);

OR

 scrollViewObject.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        scrollViewObject.getViewTreeObserver().removeOnGlobalLayoutListener(this);
        scrollViewObject.fullScroll(View.FOCUS_UP);
    }
});

The main problem to all these valid solutions is that you are trying to move up the scroll when it isn't drawn on screen yet.

You need to wait until scroll view is on screen, then move it to up with any of these solutions. This is better solution than a postdelay, because you don't mind about the delay.

    // Wait until my scrollView is ready
    scrollView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            // Ready, move up
            scrollView.fullScroll(View.FOCUS_UP);
        }
    });

Very easy

    ScrollView scroll = (ScrollView) findViewById(R.id.addresses_scroll);
    scroll.setFocusableInTouchMode(true);
    scroll.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);

I faced Same Problem When i am using Scrollview inside View Flipper or Dialog that case scrollViewObject.fullScroll(ScrollView.FOCUS_UP) returns false so that case scrollViewObject.smoothScrollTo(0, 0) is Worked for me

Scroll Focus Top

 final ScrollView scrollview = (ScrollView)findViewById(R.id.selected_place_layout_scrollview);

         scrollview.post(new Runnable() { 
                public void run() { 
                    scrollview.scrollTo(0, 0); 
                } 
            }); 

This is worked for me

scroll_view.smoothScrollTo(0,0); // scroll to top of screen

runOnUiThread( new Runnable(){
   @Override
   public void run(){
      mainScrollView.fullScroll(ScrollView.FOCUS_UP);
   }
}

I fixed my issue in Kotlin like this:

scrollview.isFocusableInTouchMode = true
scrollview.fullScroll(View.FOCUS_UP)
scrollview.smoothScrollTo(0,0)

You can also create an extension of this like:

ScrollView.moveToTop()
{
    this.isFocusableInTouchMode = true
    this.fullScroll(View.FOCUS_UP)
    this.smoothScrollTo(0,0)
}

and use it like:

scrollView.moveToTop()

This is force scroll for scrollview :

            scrollView.post(new Runnable() {
                @Override
                public void run() {
                    scrollView.scrollTo(0, 0);
                    scrollView.pageScroll(View.FOCUS_UP);
                    scrollView.smoothScrollTo(0,0);
                }
            });

scrollView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        // Ready, move up
        scrollView.fullScroll(View.FOCUS_UP);
    }
});

This solution also works for NestedScrollView

NestedScrollView nestedScrollView = view.findViewById(R.id.YourNestedScrollViewID);
nestedScrollView.fullScroll(ScrollView.FOCUS_UP);

@SuppressWarnings({ "deprecation", "unchecked" })
public void swipeTopToBottom(AppiumDriver<MobileElement> driver) 
                    throws InterruptedException {
       Dimension dimensions = driver.manage().window().getSize();
        Double screenHeightStart = dimensions.getHeight() * 0.30;
        int scrollStart = screenHeightStart.intValue();
        System.out.println("s="+scrollStart);
        Double screenHeightEnd = dimensions.getHeight()*0.90;
        int scrollEnd = screenHeightEnd.intValue();
        driver.swipe(0,scrollStart,0,scrollEnd,2000);
        CommonUtils.threadWait(driver, 3000);
    }

A few years later, the only proper solution is a mix of this thread:

without a listener or a post delayed handler, simpler solutions will fail because the can try to scroll before the ScrollView is drawn on the screen like explained by @Pelanes

the most proposed answer scan_settings_sv.fullScroll(View.FOCUS_UP); will move view to the first focusable element, not necessarily the top of scroll view. So, if there is a header or some text, or disabled views greyed out, and and a TextView below them, the ScrollView will move up to the TextView and not ScrollView Header

Like @Nilhcem commented, we need to remove the listener at the end, else the ScrollView will keep moving up

I also implemented it with the global OnGlobalLayoutListener reference as method argument to fix compiler warnings

So, the final solution should implement view.smoothScrollTo(0,0);, combined with OnGlobalLayoutListener to ensure the view was properly drwan on screen:

final ScrollView my_view= dialog.findViewById(R.id.my_view_id);
scan_settings_sv.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        // Ready, move up
        //my_view.fullScroll(View.FOCUS_UP); //moves up to the to selectable/focusable element
        my_view.smoothScrollTo(0,0); // scrolls to top of view
        my_view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
    }
});

Note that it is very important to get the ScrollView just before invoking the method! Else, if the view height changed after the first final ScrollView my_view= dialog.findViewById(R.id.my_view_id); invocation, for example because a ListView below the ScrollView was expanded, the scroll will not properly reach top of the ScrollView