在Android中按像素滚动列表视图

支持的滚动列表的方式 ListView

mListView.smoothScrollToPosition(position);

http://developer.android.com/reference/android/widget/AbsListView.html#smoothScrollToPosition(int)

但是,由于您特别提到要垂直偏移视图,因此必须调用:

mListView.setSelectionFromTop(position, yOffset);

http://developer.android.com/reference/android/widget/ListView.html#setSelectionFromTop(int,%20int)

smoothScrollByOffset(yOffset) . 但是,它仅在API上受支持>=11

http://developer.android.com/reference/android/widget/ListView.html#smoothScrollByOffset(int)

trackMotionScroll

public class FutureListView {

    private final ListView mView;

    public FutureListView(ListView view) {
        mView = view;
    }

    /**
     * Scrolls the list items within the view by a specified number of pixels.
     *
     * @param y the amount of pixels to scroll by vertically
     */
    public void scrollListBy(int y) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            mView.scrollListBy(y);
        } else {
            // scrollListBy just calls trackMotionScroll
            trackMotionScroll(-y, -y);
        }
    }

    private void trackMotionScroll(int deltaY, int incrementalDeltaY) {
        try {
            Method method = AbsListView.class.getDeclaredMethod("trackMotionScroll", int.class, int.class);
            method.setAccessible(true);
            method.invoke(mView, deltaY, incrementalDeltaY);
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        };
    }
}

ListView 子类。它可以很容易地进行调整,以便在活动代码中使用。

getListItemsHeight() 返回列表的总像素高度,并用每个项目的垂直像素偏移量填充数组。虽然这些信息是有效的, getListScrollY() 返回当前垂直像素滚动位置,然后 scrollListToY() 如果列表的大小或内容发生变化, getListItemsHight() 必须再打一次电话。

private int m_nItemCount;
private int[] m_nItemOffY;

private int getListItemsHeight() 
{  
    ListAdapter adapter = getAdapter();  
    m_nItemCount = adapter.getCount();
    int height = 0;
    int i;

    m_nItemOffY = new int[m_nItemCount];

    for(i = 0; i< m_nItemCount; ++i){ 
        View view  = adapter.getView(i, null, this);  

        view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
                    MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));  

        m_nItemOffY[i] = height;
        height += view.getMeasuredHeight();
    }  

    return height;  
}  

private int getListScrollY()
{
    int pos, nScrollY, nItemY;
    View view;

    pos = getFirstVisiblePosition();
    view = getChildAt(0);
    nItemY = view.getTop();
    nScrollY = m_nItemOffY[pos] - nItemY;

    return nScrollY;
}

private void scrollListToY(int nScrollY)
{
    int i, off;

    for(i = 0; i < m_nItemCount; ++i){
        off = m_nItemOffY[i] - nScrollY;
        if(off >= 0){
            setSelectionFromTop(i, off);
            break;
        }
    }
}

目前,ListViewCompat可能是一个更好的解决方案。

android.support.v4.widget.ListViewCompat.scrollListBy(@NonNull ListView listView, int y)

如果你想按像素移动,你可以用这个

public void scrollBy(ListView l, int px){
    l.setSelectionFromTop(l.getFirstVisiblePosition(),l.getChildAt(0).getTop() - px);
}