ViewPager in SwipeRefreshLayout

Question

我有ViewPager由带有列表的片段组成。我想把它放在SwipeRefreshLayout，以更新所有的轨道在一次。当我向下滚动任何SvipeRefresh动画中的元素列表时，就会启动。仅当当前列表位于初始位置时，如何创建它？

public static  MainList getInstanse(int position){
        MainList mainList  = new MainList();
        Bundle args = new Bundle();
        args.putInt("pos", position);
        mainList.setArguments(args);
        return mainList;
}




       Bundle bundle= getArguments();
       bs = new AdapterForListView();
       lvMain = (ListView) rootView.findViewById(R.id.lvMain);

       if(bundle!=null) {

               bs = new AdapterForListView();
               addItems(bundle.getInt("pos"));
               bs.InForEntries(getActivity(), itemsArray);
               lvMain.setAdapter(bs);
               lvMain.setDividerHeight(2);

               lvMain.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                       @Override
                       public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                               Intent intent = new Intent(getActivity(), ViewMagazin.class);

                               intent.putExtra("EXTRA_SESSION_ID", itemsArray.get(position).getIdSale());
                               startActivity(intent);
                       }
               });
               //View c = lvMain.getChildAt(0);
               //scrollyF = -c.getTop() + lvMain.getFirstVisiblePosition() * c.getHeight();
       }

       return rootView;
}` 

Answer 1

谷歌解决这个问题的例子张贴在谷歌示例github项目上。

创建一个扩展原始SwipeRefreshLayout的视图：

/*
 * Copyright 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.swiperefreshmultipleviews;

import android.content.Context;
import android.support.v4.view.ViewCompat;
import android.support.v4.widget.SwipeRefreshLayout;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AbsListView;

/**
 * A descendant of {@link android.support.v4.widget.SwipeRefreshLayout} which supports multiple
 * child views triggering a refresh gesture. You set the views which can trigger the gesture via
 * {@link #setSwipeableChildren(int...)}, providing it the child ids.
 */
public class MultiSwipeRefreshLayout extends SwipeRefreshLayout {

    private View[] mSwipeableChildren;

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

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

    /**
     * Set the children which can trigger a refresh by swiping down when they are visible. These
     * views need to be a descendant of this view.
     */
    public void setSwipeableChildren(final int... ids) {
        assert ids != null;

        // Iterate through the ids and find the Views
        mSwipeableChildren = new View[ids.length];
        for (int i = 0; i < ids.length; i++) {
            mSwipeableChildren[i] = findViewById(ids[i]);
        }
    }

    // BEGIN_INCLUDE(can_child_scroll_up)
    /**
     * This method controls when the swipe-to-refresh gesture is triggered. By returning false here
     * we are signifying that the view is in a state where a refresh gesture can start.
     *
     * <p>As {@link android.support.v4.widget.SwipeRefreshLayout} only supports one direct child by
     * default, we need to manually iterate through our swipeable children to see if any are in a
     * state to trigger the gesture. If so we return false to start the gesture.
     */
    @Override
    public boolean canChildScrollUp() {
        if (mSwipeableChildren != null && mSwipeableChildren.length > 0) {
            // Iterate through the scrollable children and check if any of them can not scroll up
            for (View view : mSwipeableChildren) {
                if (view != null && view.isShown() && !canViewScrollUp(view)) {
                    // If the view is shown, and can not scroll upwards, return false and start the
                    // gesture.
                    return false;
                }
            }
        }
        return true;
    }
    // END_INCLUDE(can_child_scroll_up)

    // BEGIN_INCLUDE(can_view_scroll_up)
    /**
     * Utility method to check whether a {@link View} can scroll up from it's current position.
     * Handles platform version differences, providing backwards compatible functionality where
     * needed.
     */
    private static boolean canViewScrollUp(View view) {
        if (android.os.Build.VERSION.SDK_INT >= 14) {
            // For ICS and above we can call canScrollVertically() to determine this
            return ViewCompat.canScrollVertically(view, -1);
        } else {
            if (view instanceof AbsListView) {
                // Pre-ICS we need to manually check the first visible item and the child view's top
                // value
                final AbsListView listView = (AbsListView) view;
                return listView.getChildCount() > 0 &&
                        (listView.getFirstVisiblePosition() > 0
                                || listView.getChildAt(0).getTop() < listView.getPaddingTop());
            } else {
                // For all other view types we just check the getScrollY() value
                return view.getScrollY() > 0;
            }
        }
    }
    // END_INCLUDE(can_view_scroll_up)
}

在xml布局中使用此视图：

<com.example.android.swiperefreshmultipleviews.MultiSwipeRefreshLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/swiperefresh"
      android:layout_width="match_parent"
      android:layout_height="match_parent">

    <!-- your code -->

</com.example.android.swiperefreshmultipleviews.MultiSwipeRefreshLayout>

在您的活动或片段中，您可以在以下情况下使用此组件：

mSwipeRefreshLayout = (MultiSwipeRefreshLayout) view.findViewById(R.id.swiperefresh);
mSwipeRefreshLayout.setSwipeableChildren(android.R.id.list, android.R.id.empty);

android.R.id.list和android.R.id.empty是您的列表或回收器视图的is。视图很好地处理两个ids相同的列表。

您可以在google-示例github项目上看到真正的示例。

Answer 2

您可以在初始位置设置SwipeRefreshLayout刷新启用，在其他位置设置禁用。

Answer 3

我有一个FragmentContainer作为SwipeRefreshLayout的子代，而在我的片段中有一个RecyclerView (对于片段来说这是非常正常的)。

SwipeRefreshLayout正在给列表卷轴带来问题，我正在使用这个扩展函数来解决这个问题。方法是不言自明的，尽管我会留下我的评论。我希望它能帮助人们。

/**
 * This method binds [SwipeRefreshLayout] to child [RecyclerView].
 * Normally if RefreshLayout is the direct parent of RecyclerView scrolling is handled internally.
 * However, sometimes we have multiple recyclerViews inside RefreshLayout or recyclerViews are inside
 * a ViewPager. In this cases, scrolling up will have problems. To tackle this scrolling issues we
 * are disabling/enabling refreshLayout depending on the recyclerView.
 *
 * @param refreshLayout to be bounded with.
 * @see [InprogressInspectionFragment.initRecyclerView]
 * and [OutstandingInspectionFragment.initRecyclerView]
 */
fun RecyclerView.refreshLayoutPatched(refreshLayout: SwipeRefreshLayout){
    val marginTop = (layoutParams as ConstraintLayout.LayoutParams).topMargin

    addOnScrollListener(object : RecyclerView.OnScrollListener(){
        override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            recyclerView.getChildAt(0)?.let{
                refreshLayout.isEnabled =
                    (layoutManager as LinearLayoutManager).findFirstVisibleItemPosition() == 0
                            && recyclerView.getChildAt(0).top == marginTop
            }
        }
    })

}