pulltorefresh 实现瀑布流的方式（基于recycleview）

我在项目中的需求是：

1、项目本身我是集进人了pulltofresh的类库实现下拉刷新及上拉加载

2、某一个页面要实现瀑布流的形式，第一想到的是recycleview的staggredGridLayoutManager 的布局管理器实现。

3、将pulltoRefresh的控件对recycleview实现扩展

4、处理下拉、上拉之后的逻辑

一、实现的第一步：

要想用pulltorefresh实现下拉刷新，你首先得导入pulltorefresh的类库，具体的代码先不细说了。

如图：

二、添加recycleview的依赖

  compile 'com.android.support:cardview-v7:23.1.0'
    compile 'com.android.support:recyclerview-v7:23.1.0'

三、在导入的pulltofresh 的类库中添加一个支持recycleview的类

package com.sinolbs.seeyou.pulltorefresh.library.extras.recyclerview;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.util.AttributeSet;import android.view.View;import com.sinolbs.seeyou.pulltorefresh.library.PullToRefreshBase;/** * Created by Administrator on 2017/11/7. * pulltorefresh扩展recycleview; * 实现recycle的下拉刷新 * */public class PullToRefreshRecycleView  extends PullToRefreshBase<RecyclerView> {    private RecyclerView mRecyclerView;    public PullToRefreshRecycleView(Context context) {        super(context);    }    public PullToRefreshRecycleView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public PullToRefreshRecycleView(Context context, PullToRefreshBase.Mode mode) {        super(context, mode);    }    public PullToRefreshRecycleView(Context context, Mode mode, AnimationStyle style) {        super(context, mode, style);    }    @Override    public final Orientation getPullToRefreshScrollDirection() {        return Orientation.VERTICAL;    }    @Override    protected RecyclerView createRefreshableView(Context context,                                                 AttributeSet attrs) {        mRecyclerView = new RecyclerView(context, attrs);        return mRecyclerView;    }    @Override    protected boolean isReadyForPullStart() {        return isFirstItemVisible();    }    @Override    protected boolean isReadyForPullEnd() {        return isLastItemVisible();    }    /**     * @Description: 判断第一个条目是否完全可见     *     * @return boolean:     * @version 1.0     * @date 2015-9-23     * @Author zhou.wenkai     */    private boolean isFirstItemVisible() {        final RecyclerView.Adapter<?> adapter = getRefreshableView().getAdapter();        // 如果未设置Adapter或者Adapter没有数据可以下拉刷新        if (null == adapter || adapter.getItemCount() == 0) {            return true;        } else {            // 第一个条目完全展示,可以刷新            if (getFirstVisiblePosition() == 0) {                return mRecyclerView.getChildAt(0).getTop() >= mRecyclerView                        .getTop();            }        }        return false;    }    /**     * @Description: 获取第一个可见子View的位置下标     *     * @return int: 位置     * @version 1.0     * @date 2015-9-23     * @Author zhou.wenkai     */    private int getFirstVisiblePosition() {        View firstVisibleChild = mRecyclerView.getChildAt(0);        return firstVisibleChild != null ? mRecyclerView                .getChildAdapterPosition(firstVisibleChild) : -1;    }    /**     * @Description: 判断最后一个条目是否完全可见     *     * @return boolean:     * @version 1.0     * @date 2015-9-23     * @Author zhou.wenkai     */    private boolean isLastItemVisible() {        final RecyclerView.Adapter<?> adapter = getRefreshableView().getAdapter();        // 如果未设置Adapter或者Adapter没有数据可以上拉刷新        if (null == adapter || adapter.getItemCount() == 0) {            return true;        } else {            // 最后一个条目View完全展示,可以刷新            int lastVisiblePosition = getLastVisiblePosition();            if(lastVisiblePosition >= mRecyclerView.getAdapter().getItemCount()-1) {                return mRecyclerView.getChildAt(                        mRecyclerView.getChildCount() - 1).getBottom() <= mRecyclerView                        .getBottom();            }        }        return false;    }    /**     * @Description: 获取最后一个可见子View的位置下标     *     * @return int: 位置     * @version 1.0     * @date 2015-9-23     * @Author zhou.wenkai     */    private int getLastVisiblePosition() {        View lastVisibleChild = mRecyclerView.getChildAt(mRecyclerView                .getChildCount() - 1);        return lastVisibleChild != null ? mRecyclerView                .getChildAdapterPosition(lastVisibleChild) : -1;    }}

四、对控件进行引用

  <com.sinolbs.seeyou.pulltorefresh.library.extras.recyclerview.PullToRefreshRecycleView            xmlns:ptr="http://schemas.android.com/apk/res-auto"            android:id="@+id/recycle_view"            android:layout_width="fill_parent"            android:layout_height="fill_parent"            ptr:ptrMode="both"            ptr:ptrHeaderBackground="@color/edittext_bg"            ptr:ptrHeaderTextColor="@color/text_gray"            />

五、使用的方法

  mRecycle_view = (PullToRefreshRecycleView) baseview.findViewById(R.id.recycle_view);

 //获取pulltofresh的实体控件        final RecyclerView refreshableView = mRecycle_view.getRefreshableView();        StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(2,StaggeredGridLayoutManager.VERTICAL);        SpacesItemDecoration decoration=new SpacesItemDecoration(8);        refreshableView.addItemDecoration(decoration);        layoutManager.setReverseLayout(false);        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);        refreshableView.setLayoutManager(layoutManager);        // 设置item动画        refreshableView.setItemAnimator(new DefaultItemAnimator());        RecommendGridAdapter gridAdapter = new RecommendGridAdapter(getActivity(), datas);        //2.设置adapter        refreshableView.setAdapter(gridAdapter);        gridAdapter.getRandomHeight(datas);        mRecycle_view.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<RecyclerView>() {            @Override            public void onPullDownToRefresh(PullToRefreshBase<RecyclerView> refreshView) {                Toast.makeText(getActivity(), "Pull Down!", Toast.LENGTH_SHORT).show();                new Handler().postDelayed(new Runnable(){                    @Override                    public void run() {                        Log.e("延时两秒","延时两秒检索");                        mRecycle_view.onRefreshComplete();                    }                }, 3000);            }            @Override            public void onPullUpToRefresh(PullToRefreshBase<RecyclerView> refreshView) {                Toast.makeText(getActivity(), "Pull Up!", Toast.LENGTH_SHORT).show();            }        });

六、完美实现

欧耶！！！