编写用到的下拉刷新的布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#f00"
android:gravity="center"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/ll"
>
<TextView
android:id="@+id/status"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="显示一些东西"
android:textColor="#000"
/>
</LinearLayout>
</LinearLayout>自定义RecyclerView 封装了下拉刷新和加载更多的功能
/**
* 下拉刷新和加载更多的 自定View
* Created by SwmIsMe on 2017/3/2.
*/
public class MyRecyclerView extends RecyclerView {
public final static int STATE_NORMAL = 0;
public final static int STATE_READY = 1;
public final static int STATE_REFRESHING = 2;
MyLoadRefreshAdapter mLoadRefreshAdapter;
View headerView, footerView;
private int mState = STATE_NORMAL;
// 头布局的高度
int headerViewHeight;
// 是否正在触摸
boolean isOnTouching;
TextView status;
boolean isRefresh;
private LinearLayout mLl;
private LinearLayout.LayoutParams mParams;
private LayoutManager mLayoutManager;
public MyRecyclerViewListener getMyRecyclerViewListener() {
return myRecyclerViewListener;
}
// 设置 监听
public void setMyRecyclerViewListener(MyRecyclerViewListener myRecyclerViewListener) {
this.myRecyclerViewListener = myRecyclerViewListener;
}
MyRecyclerViewListener myRecyclerViewListener;
public MyRecyclerView(Context context) {
super(context);
}
public MyRecyclerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public MyRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
int lastX, lastY;
@Override
public boolean onTouchEvent(MotionEvent e) {
int x = (int) e.getX();
int y = (int) e.getY();
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
break;
case MotionEvent.ACTION_MOVE:
isOnTouching = true;
// 获取到 轮播的view
View view1 = this.getChildAt(1);
// 获取到 轮播的view安排的位置.
int loopViewPagerPosition = this.getChildLayoutPosition(view1);
// 如果 轮播的view安排(layout)的位置. 是第一个 触发下拉刷新的操作.
if (loopViewPagerPosition == 1) {
if (lastY == 0) {
lastY = y;
}
int dy = lastY - y;
int dx = lastX - x;
int yabs = Math.abs(dy);
int xabs = Math.abs(dx);
if (yabs > xabs) {
isRefresh = true;
changeHeight(dy);
this.requestDisallowInterceptTouchEvent(true);
} else {
this.requestDisallowInterceptTouchEvent(false);
}
lastX = x;
lastY = y;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
isRefresh = false;
isOnTouching = false;
// 归零
lastY = 0;
// 开始刷新
if (mState == STATE_READY || mState == STATE_REFRESHING) {
onStatusChange(STATE_REFRESHING);
autoSize(0);
}
// 回归到 隐藏的位置
if (mState == STATE_NORMAL) {
autoSize(-headerViewHeight);
}
break;
}
return super.onTouchEvent(e);
}
// 通过改变 topMargin的值.改变高度
private void changeHeight(int dy) {
mParams.topMargin -= dy;
int margin = mParams.topMargin;
mLl.setLayoutParams(mParams);
setStateByHeight(margin, false);
}
/**
* 更新 头布局的高度
*
* @param targetHeight 要改变到的高度 当这个高度为0时,topMargin为0,显示整个刷新的界面,
* -headerViewHeight 隐藏头布局
*/
public void autoSize(int targetHeight) {
int currentHeight = mParams.topMargin;
// 从当前高度 到 目前高度,的动画变化值.
ValueAnimator objectAnimator = ValueAnimator.ofInt(currentHeight, targetHeight);
// 设置下拉刷新的高度
objectAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int animatedValue = (int) animation.getAnimatedValue();
// 根据高度设置文本
setStateByHeight(animatedValue, true);
mParams.topMargin = animatedValue;
mLl.setLayoutParams(mParams);
}
});
objectAnimator.start();
}
// 设置加载更多的判断
@Override
public void setLayoutManager(final LayoutManager layout) {
super.setLayoutManager(layout);
this.addOnScrollListener(new OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
}
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if (isRefresh) {
return;
}
if (mState != STATE_NORMAL) {
return;
}
LogUtils.e("new state" + newState);
//判断是否最后一item个显示出来
mLayoutManager = getLayoutManager();
//可见的item个数
int visibleChildCount = mLayoutManager.getChildCount();
// 如果大于0 并且 状态不等于空闲 并且 没有在加载更多
if (visibleChildCount > 0 && newState == RecyclerView.SCROLL_STATE_IDLE && !isLoadMore) {
// 获取最后一个 view 除加载更多view
View lastVisibleView = recyclerView.getChildAt(recyclerView.getChildCount() - 1);
// 返回给定子视图的适配器位置
int lastVisiblePosition = recyclerView.getChildLayoutPosition(lastVisibleView);
// 如果 最后一个可见的位置 大于等于
if (lastVisiblePosition >= mLayoutManager.getItemCount() - 1) {
// 加载更多view 可见
footerView.setVisibility(VISIBLE);
isLoadMore = true;
// 加载更多
if (myRecyclerViewListener != null) {
myRecyclerViewListener.onLoadMore();
}
} else {
footerView.setVisibility(GONE);
}
}
}
});
}
// 根据高度来设置 现在的状态
private void setStateByHeight(int height, boolean isAuto) {
if (mState == STATE_REFRESHING) {
return;
}
// 如果 当前的高度 小于 头布局的高度
if (height < headerViewHeight) {
onStatusChange(STATE_NORMAL);
} else if (height > headerViewHeight) {
onStatusChange(STATE_READY);
} else if (height == headerViewHeight && !isOnTouching && !isAuto) {
onStatusChange(STATE_REFRESHING);
}
}
boolean isLoadMore;
public void onStatusChange(int status) {
mState = status;
switch (status) {
case STATE_READY:
this.status.setText("松开刷新...");
break;
case STATE_NORMAL:
this.status.setText("下拉刷新...");
break;
case STATE_REFRESHING:
this.status.setText("正在刷新...");
if (myRecyclerViewListener != null) {
myRecyclerViewListener.onRefresh();
}
break;
}
}
// 初始化头尾布局 和 头尾view的适配器
@Override
public void setAdapter(Adapter adapter) {
ArrayList<View> headers = new ArrayList<>();
ArrayList<View> footers = new ArrayList<>();
// 加载下拉刷新的布局文件
View refreshView = LayoutInflater.from(getContext()).inflate(R.layout.item_recycler_refresh, null);
headerView = refreshView;
status = (TextView) refreshView.findViewById(R.id.status);
mLl = (LinearLayout) refreshView.findViewById(R.id.ll);
headerView.post(new Runnable() {
@Override
public void run() {
// 头布局真正的高度
headerViewHeight = headerView.getHeight();
// 设置layout参数 隐藏头布局
mParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
mParams.topMargin = -headerViewHeight;
mParams.width = ScreenUtils.screenW;
mLl.setLayoutParams(mParams);
}
});
// 将头布局添加到 集合中
headers.add(headerView);
// 初始化 尾布局
LinearLayout footerLayout = new LinearLayout(getContext());
footerLayout.setGravity(Gravity.CENTER);
footerLayout.setLayoutParams(new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
footers.add(footerLayout);
footerLayout.setPadding(0, 15, 0, 15);
footerLayout.addView(new ProgressBar(getContext(), null, android.R.attr.progressBarStyleSmall));
TextView text = new TextView(getContext());
text.setText("正在加载...");
footerLayout.addView(text);
footerView = footerLayout;
footerView.setVisibility(GONE);
// 初始化 适配器
mLoadRefreshAdapter = new MyLoadRefreshAdapter(adapter, headers, footers);
super.setAdapter(mLoadRefreshAdapter);
}
public interface MyRecyclerViewListener {
void onRefresh();
void onLoadMore();
}
// 完成加载更多
public void setLoadMoreComplete() {
// 直接隐藏 尾布局
footerView.setVisibility(GONE);
isLoadMore = false;
}
// 完成下拉刷新
public void setRefreshComplete() {
onStatusChange(STATE_NORMAL);
autoSize(-headerViewHeight);
}
}自定义 MyLoadRefreshAdapter 适配器
/**
* 实现显示头部和尾部item的adapter,把头部尾部的事情交给这个adapter来做,其他的交给子adapter
* Created by SwmIsMe on 2017/3/2.
*/
public class MyLoadRefreshAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
public ArrayList<View> headerViews = new ArrayList<>();
public ArrayList<View> footViews = new ArrayList<>();
public RecyclerView.Adapter adapter;
public MyLoadRefreshAdapter(RecyclerView.Adapter adapter, ArrayList<View> headerViews, ArrayList footViews) {
this.adapter = adapter;
this.headerViews = headerViews;
this.footViews = footViews;
}
MyLoadRefreshListener mLoadRefreshListener;
public MyLoadRefreshListener getLoadRefreshListener() {
return mLoadRefreshListener;
}
public void setLoadRefreshListener(MyLoadRefreshListener loadRefreshListener) {
mLoadRefreshListener = loadRefreshListener;
}
public interface MyLoadRefreshListener {
// 获取现在item的类型
void getNowItemType(int itemPosition);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == RecyclerView.INVALID_TYPE) {
//头部item
return new RecyclerView.ViewHolder(headerViews.get(0)) {
};
} else if (viewType == (RecyclerView.INVALID_TYPE - 1)) {
//尾部item
return new RecyclerView.ViewHolder(footViews.get(0)) {
};
}
return adapter.onCreateViewHolder(parent, viewType);
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (position >= 0 && position < headerViews.size()) {
return;
}
// 交给 其他的适配器处理
if (adapter != null) {
int p = position - headerViews.size();
if (p < adapter.getItemCount()) {
adapter.onBindViewHolder(holder, p);
}
}
}
@Override
public int getItemViewType(int position) {
if (position >= 0 && position < headerViews.size()) {
//如果是头部则返回一个不可用的标识,表示这是头部item
return RecyclerView.INVALID_TYPE;
}
if (adapter != null) {
int p = position - headerViews.size();
if (p < adapter.getItemCount()) {
return adapter.getItemViewType(p);
}
}
return RecyclerView.INVALID_TYPE - 1;//默认返回表示是尾部的item
}
@Override
public int getItemCount() {
return getCount();
}
public int getCount() {
int count = headerViews.size() + footViews.size();
if (adapter != null) {
count += adapter.getItemCount();
}
return count;
}
}使用,添加监听
mHomeRecyclerview.setLayoutManager(new LinearLayoutManager(getContext()));
MyHomeRecyclerviewAdapter adapter = new MyHomeRecyclerviewAdapter(LayoutInflater.from(getContext()));
mHomeRecyclerview.setAdapter(adapter);
// 设置 下拉刷新 和加载更多的 监听
mHomeRecyclerview.setMyRecyclerViewListener(new MyRecyclerView.MyRecyclerViewListener() {
@Override
public void onRefresh() {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
ToastUtils.showToast("onRefresh");
mHomeRecyclerview.setRefreshComplete();
}
}, 2000);
}
@Override
public void onLoadMore() {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
ToastUtils.showToast("onLoadMore");
mHomeRecyclerview.setLoadMoreComplete();
}
}, 2000);
}
});
本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。
