Android：Horizo​​ntalScrollView smoothScroll 动画时间

Question

I have a situation in that I am using a horizontal scroll view with images and using buttons to smooth scroll to the different image locations. Now it works okay I was just wondering if anyone knew of anyway to slow down the smooth scroll method, ie having a longer annimation time? As currently the snapping happens pretty quickly.

Perhaps through an override of the smoothscroll, I have tried to search for this/examples but to no luck.

So any ideas?

Thanks,

Si

Answer 1

How About:

ObjectAnimator animator=ObjectAnimator.ofInt(yourHorizontalScrollView, "scrollX",targetXScroll );
animator.setDuration(800);
animator.start();

Answer 2

THis is one way, which works well for me:

    new CountDownTimer(2000, 20) { 

        public void onTick(long millisUntilFinished) { 
            hv.scrollTo((int) (2000 - millisUntilFinished), 0); 
        } 

        public void onFinish() { 

        } 
     }.start();

So here the horizontal scroll view (hv) moves in two seconds from position 0 to 2000 or to the end of the view if smaller than 2000px. Easy to adjust...

Answer 3

Subclass HorizontalScrollView, use reflection to get access to the private field mScroller in HorizontalScrollView. Of course, this will break if the underlying class changes the field name, it defaults back to original scroll implemenation.

The call myScroller.startScroll(scrollX, getScrollY(), dx, 0, 500); changes the scroll speed.

private OverScroller myScroller;     

private void init()
{
    try
    {
        Class parent = this.getClass();
        do
        {
            parent = parent.getSuperclass();
        } while (!parent.getName().equals("android.widget.HorizontalScrollView"));

        Log.i("Scroller", "class: " + parent.getName());
        Field field = parent.getDeclaredField("mScroller");
        field.setAccessible(true);
        myScroller = (OverScroller) field.get(this);

    } catch (NoSuchFieldException e)
    {
        e.printStackTrace();
    } catch (IllegalArgumentException e)
    {
        e.printStackTrace();
    } catch (IllegalAccessException e)
    {
        e.printStackTrace();
    }
}

public void customSmoothScrollBy(int dx, int dy)
{
    if (myScroller == null)
    {
        smoothScrollBy(dx, dy);
        return;
    }

    if (getChildCount() == 0)
        return;

    final int width = getWidth() - getPaddingRight() - getPaddingLeft();
    final int right = getChildAt(0).getWidth();
    final int maxX = Math.max(0, right - width);
    final int scrollX = getScrollX();
    dx = Math.max(0, Math.min(scrollX + dx, maxX)) - scrollX;

    myScroller.startScroll(scrollX, getScrollY(), dx, 0, 500);
    invalidate();
}

public void customSmoothScrollTo(int x, int y)
{
    customSmoothScrollBy(x - getScrollX(), y - getScrollY());
}

Answer 4

Its a scroller the scroll automatically and continously. It was made to show a credits screen by continously scrolling through a list of images. This might help you or give you some idea.

https://github.com/blessenm/SlideshowDemo

Answer 5

Use .smoothScrollToPositionFromTop instead. Example

listView.smoothScrollToPositionFromTop(scroll.pos(),0,scroll.delay());

where scroll is a simple variable from a class that takes current screen position .get() returns new position .pos() and time of smooth scrolling .delay ... etc

Answer 6

Or even easier, .smoothScrollTo() . Example:

hsv.smoothScrollTo(x, y);

Docs: Android Developer ScrollView docs

Answer 7

Have a look at http://developer.android.com/reference/android/widget/Scroller.html :

The duration of the scroll can be passed in the constructor and specifies the maximum time that the scrolling animation should take