带加载更过功能的LoadMoreRecyclerView

类实现

/**
*
* 添加加载更多功能
* Created by chs .
*/
public class LoadMoreRecyclerView extends RecyclerView {

private boolean isScrollingToBottom = true;
private FloatingActionButton floatingActionButton;
private LoadMoreListener mLoadingListener;
private ArrayList<View> mFootViews = new ArrayList<>();

public LoadMoreRecyclerView(Context context) {
super(context);
init(context);
}

public LoadMoreRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}

private void init(Context context) {
View view = LayoutInflater.from(context).inflate(R.layout.listview_footer,null);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
view.setLayoutParams(lp);
addFootView(view);
mFootViews.get(0).setVisibility(GONE);
}
public void addFootView(final View view) {
mFootViews.clear();
mFootViews.add(view);
}
public LoadMoreRecyclerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
init(context);
}

public void applyFloatingActionButton(FloatingActionButton floatingActionButton) {
this.floatingActionButton = floatingActionButton;
}

public void setLoadMoreListener(LoadMoreListener loadMoreListener){
this.mLoadingListener = loadMoreListener;
}

@Override
public void onScrolled(int dx, int dy) {
isScrollingToBottom = dy > 0;
if (floatingActionButton != null) {
if (isScrollingToBottom) {
if (floatingActionButton.isShown())
floatingActionButton.hide();
} else {
if (!floatingActionButton.isShown())
floatingActionButton.show();
}
}
}

@Override
public void onScrollStateChanged(int state) {
if (state == RecyclerView.SCROLL_STATE_IDLE && mLoadingListener != null) {
LayoutManager layoutManager = getLayoutManager();
int lastVisibleItemPosition;
if (layoutManager instanceof GridLayoutManager) {
lastVisibleItemPosition = ((GridLayoutManager) layoutManager).findLastVisibleItemPosition();
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int[] into = new int[((StaggeredGridLayoutManager) layoutManager).getSpanCount()];
((StaggeredGridLayoutManager) layoutManager).findLastVisibleItemPositions(into);
lastVisibleItemPosition = findMax(into);
} else {
lastVisibleItemPosition = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
}
if (layoutManager.getChildCount() > 0
&& lastVisibleItemPosition >= layoutManager.getItemCount() - 1 &&  layoutManager.getItemCount() > layoutManager.getChildCount()) {
View footView = mFootViews.get(0);
footView.setVisibility(View.VISIBLE);
mLoadingListener.onLoadMore();
}
}
}
private int findMax(int[] lastPositions) {
int max = lastPositions[0];
for (int value : lastPositions) {
if (value > max) {
max = value;
}
}
return max;
}
public interface LoadMoreListener {
void onLoadMore();
}
}

底部加载更多view，listview_footer.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="3dp">
<ProgressBar
android:id="@+id/listview_foot_progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/listview_foot_more"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="5dp"
android:text="加载中..."/>

</LinearLayout>

使用,先给rvView添加底部view监听：

rvNews.setLoadMoreListener(new LoadMoreRecyclerView.LoadMoreListener() {
@Override
public void onLoadMore() {
//currentPage++;
//mPresenter.start(currentPage,type);
}
});

当无网络时，在出现加载圈后，需要进行移除，使用如下语句，即移除最后一个item（footerview）

<pre style="font-family: 宋体; font-size: 9pt; background-color: rgb(255, 255, 255);"><span style="color:#660e7a;"><strong>mAdapter</strong></span>.notifyItemRemoved(<span style="color:#660e7a;"><strong>mAdapter</strong></span>.getItemCount());