9

每次我向上或向下滚动列表时，我都会隐藏（或取消隐藏）一些视图OnScrollListener。这是附加到我的ListView.

lv.setOnScrollListener(new OnScrollListener() {

            private int mLastFirstVisibleItem;
            private boolean mIsScrollingUp = true;
            private LinearLayout ll = (LinearLayout) getActivity()
                    .findViewById(R.id.llSearchPlaces);

            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {

            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem,
                                 int visibleItemCount, int totalItemCount) {



                if (view.getId() == lv.getId()) {
                    final int currentFirstVisibleItem = lv
                            .getFirstVisiblePosition();
                    if (currentFirstVisibleItem > mLastFirstVisibleItem) {

                        if (mIsScrollingUp == true) {
                            mIsScrollingUp = false;
                             Log.i("a", "scrolling down...");

                            floatingActionButton.hide();

                            Animation animation = new TranslateAnimation(0, 0,
                                    0, 200);
                            animation.setDuration(300);
                            animation
                                    .setAnimationListener(new AnimationListener() {

                                        @Override
                                        public void onAnimationEnd(
                                                Animation animation) {
                                            ll.setVisibility(View.INVISIBLE);
                                        }

                                        @Override
                                        public void onAnimationRepeat(
                                                Animation animation) {
                                        }

                                        @Override
                                        public void onAnimationStart(
                                                Animation animation) {
                                        }
                                    });

                            ll.startAnimation(animation);
                        }

                    } else if (currentFirstVisibleItem < mLastFirstVisibleItem) {

                        if (mIsScrollingUp == false) {
                            mIsScrollingUp = true;
                            floatingActionButton.show();
                             Log.i("a", "scrolling up...");

                            Animation animation = new TranslateAnimation(0, 0,
                                    200, 0);
                            animation.setDuration(400);
                            animation
                                    .setAnimationListener(new AnimationListener() {

                                        @Override
                                        public void onAnimationEnd(
                                                Animation animation) {

                                        }

                                        @Override
                                        public void onAnimationRepeat(
                                                Animation animation) {

                                        }

                                        @Override
                                        public void onAnimationStart(
                                                Animation animation) {
                                            ll.setVisibility(View.VISIBLE);

                                        }
                                    });

                            ll.startAnimation(animation);

                        }
                    }

                    mLastFirstVisibleItem = currentFirstVisibleItem;

                }
            }
        });

布局：

<android.support.v4.widget.SwipeRefreshLayout
    android:id="@+id/swipe_refresh_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ListView
        android:id="@id/android:list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fadeScrollbars="true"
        android:listSelector="#00000000"
        android:scrollbars="none" />

</android.support.v4.widget.SwipeRefreshLayout>

自从我添加了，当我在上面的侦听器中SwipeRefreshLayout时，我什么也没得到。Log我怎样才能同时使用这两个项目？

编辑：这似乎是我需要的，但我不能让它仍然工作

作为那篇文章的一部分，我在 中添加了这个onScroll，但它似乎不起作用。

        if (firstVisibleItem == 0) {
            swipeLayout.setEnabled(true);
        } else {
            swipeLayout.setEnabled(false);
        }

EDIT2：这是问题的核心：似乎该onScroll方法在 Activity 首次启动并且列表加载时触发，然后再也不加载了。

4

3 回答 3

4

RecyclerView我对and有同样的问题ListView。向下滚动查看任何数量的项目，都无法返回列表顶部。

这将禁用SwipeRefreshLayout直到第一个可见项目或任何项目位置可见。您还可以沿此绑定不同的滚动侦听器。SwipeRefreshLayout确保在重新填充 listivew 时启用（如果以前禁用） 。

public class SwipeRefreshLayoutToggleScrollListenerListView implements AbsListView.OnScrollListener {
    private List<AbsListView.OnScrollListener> mScrollListeners = new ArrayList<AbsListView.OnScrollListener>();
    private int mExpectedVisiblePosition = 0;

    public SwipeRefreshLayoutToggleScrollListenerListView(SwipeRefreshLayout mSwipeLayout) {
        this.mSwipeLayout = mSwipeLayout;
    }

    private SwipeRefreshLayout mSwipeLayout;
    public void addScrollListener(AbsListView.OnScrollListener listener){
        mScrollListeners.add(listener);
    }
    public boolean removeScrollListener(AbsListView.OnScrollListener listener){
        return mScrollListeners.remove(listener);
    }
    public void setExpectedFirstVisiblePosition(int position){
        mExpectedVisiblePosition = position;
    }

    private void notifyOnScrolled(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount){
        for(AbsListView.OnScrollListener listener : mScrollListeners){
            listener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
        }
    }
    private void notifyScrollStateChanged(AbsListView view, int scrollState){
        for(AbsListView.OnScrollListener listener : mScrollListeners){
            listener.onScrollStateChanged(view, scrollState);
        }
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
      notifyScrollStateChanged(view, scrollState);
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        notifyOnScrolled(view, firstVisibleItem, visibleItemCount, totalItemCount);
        if(firstVisibleItem != RecyclerView.NO_POSITION)
            mSwipeLayout.setEnabled(firstVisibleItem == mExpectedVisiblePosition);
    }
}

编辑：

lv.setOnScrollListener(new SwipeRefreshLayoutToggleScrollListenerListView(mSwiperLayout){
   //override methods here, don't forget the super calls. 
});
于 2014-12-15T23:00:32.573 回答
3

您应该覆盖canChildScrollUp. SwipeRefreshView轮询此方法的目的是为了了解包含的 View 是否要向上滚动：

具有可设置界面的扩展，可用于任意包含的视图：

public class SwipeRefreshWrapper extends SwipeRefreshLayout {
    private ScrollResolver mScrollResolver;

    public SwipeRefreshWrapper(Context context) {
        super(context);
    }

    public SwipeRefreshWrapper(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setScrollResolver(ScrollResolver scrollResolver) {
        mScrollResolver = scrollResolver;
    }

    @Override
    public boolean canChildScrollUp() {
        if(mScrollResolver != null){
            return mScrollResolver.canScrollUp();
        }else {
            return super.canChildScrollUp();
        }
    }

    public static interface ScrollResolver{
        public boolean canScrollUp();
    }
}

用法（ListView也有一个不错的方法：）canScrollVertically()：

final SwipeRefreshWrapper wrapper = (SwipeRefreshWrapper) rootView.findViewById(R.id.wrapper);
final ListView list = (ListView) rootView.findViewById(R.id.list);

wrapper.setScrollResolver(new SwipeRefreshWrapper.ScrollResolver() {
                              @Override
                              public boolean canScrollUp() {
                                 return list.canScrollVertically(-1);
                              }
                          });
于 2014-12-22T19:15:19.067 回答
2 
yourListview.setOnScrollListener(new OnScrollListener() {
        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
        }
        @Override
        public void onScroll(AbsListView view, int firstVisibleItem,
                int visibleItemCount, int totalItemCount) {
            boolean enable = false;
            if(timelogListView != null && timelogListView.getChildCount() > 0){
                boolean firstItemVisible = timelogListView.getFirstVisiblePosition() == 0;
                boolean topOfFirstItemVisible = timelogListView.getChildAt(0).getTop() == 0;
                enable = firstItemVisible && topOfFirstItemVisible;
            }
            swipeLayout.setEnabled(enable); 
            if(firstVisibleItem+visibleItemCount == totalItemCount && totalItemCount!=0)
            {
                if(flag_loading == false)
                {
                    flag_loading = true;
                    ConnectionDetector conn = new ConnectionDetector(getActivity());
                    if(conn.isConnectingToInternet()){
                        // call for your pagination async
                    }else{

                    }
                }
            }
        }
    });

默认情况下：private boolean flag_loading = false; 并在您的分页 async if(YourListview.size() < 20) { flag_loading = true; } 其他{ flag_loading = false; }

于 2014-12-22T11:42:49.903 回答