自定义下拉加载上拉刷新

package cn.mvp.test;

import android.content.Context;
import android.support.v4.widget.SwipeRefreshLayout;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;

import cn.mvp.R;
import cn.mvp.mlibs.log.Log;

/**
* 继承自SwipeRefreshLayout,从而实现滑动到底部时上拉加载更多的功能.
*
* @author mrsimple
*/
public class RefreshLayout extends SwipeRefreshLayout implements AbsListView.OnScrollListener, SwipeRefreshLayout.OnRefreshListener {

/**
* 滑动到最下面时的上拉操作
*/

private int mTouchSlop;
/**
* listview实例
*/
private ListView mListView;

/**
* 上拉监听器, 到了最底部的上拉加载操作
*/
private OnLoadListener mOnLoadListener;

/**
* ListView的加载中footer
*/
private View mListViewFooter;

/**
* 按下时的y坐标
*/
private int mYDown;
/**
* 抬起时的y坐标, 与mYDown一起用于滑动到底部时判断是上拉还是下拉
*/
private int mLastY;
/**
* 是否在加载中 ( 上拉加载更多 )
*/
private boolean isLoading = false;

/**
* @param context
*/
public RefreshLayout(Context context) {
this(context, null);
}

public RefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);

mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();

mListViewFooter = LayoutInflater.from(context).inflate(R.layout.listview_footer, null, false);
}

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);

// 初始化ListView对象
if (mListView == null) {
getListView();
}
}

/**
* 获取ListView对象
*/
private void getListView() {
int childs = getChildCount();
if (childs > 0) {
View childView = getChildAt(0);
if (childView instanceof ListView) {
mListView = (ListView) childView;
// 设置滚动监听器给ListView, 使得滚动的情况下也可以自动加载
mListView.setOnScrollListener(this);
Log.d(VIEW_LOG_TAG, "### 找到listview");
}
}
}

/*
* (non-Javadoc)
* @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)
*/
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
final int action = event.getAction();

switch (action) {
case MotionEvent.ACTION_DOWN:
// 按下
mYDown = (int) event.getRawY();
break;

case MotionEvent.ACTION_MOVE:
// 移动
mLastY = (int) event.getRawY();
break;

case MotionEvent.ACTION_UP:
// 抬起
if (canLoad()) {
loadData();
}
break;
default:
break;
}

return super.dispatchTouchEvent(event);
}

/**
* 是否可以加载更多, 条件是到了最底部, listview不在加载中, 且为上拉操作.
*
* @return
*/
private boolean canLoad() {
return isBottom() && !isLoading && isPullUp();
}

/**
* 判断是否到了最底部
*/
private boolean isBottom() {

if (mListView != null && mListView.getAdapter() != null) {
return mListView.getLastVisiblePosition() == (mListView.getAdapter().getCount() - 1);
}
return false;
}

/**
* 是否是上拉操作
*
* @return
*/
private boolean isPullUp() {
return (mYDown - mLastY) >= mTouchSlop;
}

/**
* 如果到了最底部,而且是上拉操作.那么执行onLoad方法
*/
private void loadData() {
if (mOnLoadListener != null) {
// 设置状态
setLoading(true);
//
mOnLoadListener.onLoad();
}
if (mOnRefChangeListener != null) {
// 设置状态
setLoading(true);
mOnRefChangeListener.onLoad();
}
}

/**
* @param loading
*/
public void setLoading(boolean loading) {
isLoading = loading;
if (isLoading) {
mListView.addFooterView(mListViewFooter);
} else {
mListView.removeFooterView(mListViewFooter);
mYDown = 0;
mLastY = 0;
}
}

/**
* @param loading
*/
public void loadingFinish(boolean loading) {
String s = loading ? "暂无数据" : "";
isLoading = false;
mListView.removeFooterView(mListViewFooter);
mYDown = 0;
mLastY = 0;
}

/**
* @param loadListener
*/
public void setOnLoadListener(OnLoadListener loadListener) {
mOnLoadListener = loadListener;
}

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

}

@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
int totalItemCount) {
// 滚动时到了最底部也可以加载更多
if (canLoad()) {
loadData();
}
}

@Override
public void onRefresh() {
if (mOnRefChangeListener != null) {
mOnRefChangeListener.onRefresh();
}
}

public void setAdapter(BaseAdapter baseAdapter) {
mListView.setAdapter(baseAdapter);
}

public void setOnItemClickListener(AdapterView.OnItemClickListener onItemClickListener) {
mListView.setOnItemClickListener(onItemClickListener);
}

public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener onItemLongClickListener) {
mListView.setOnItemLongClickListener(onItemLongClickListener);
}

/**
* 加载更多的监听器
*
* @author mrsimple
*/
public interface OnRefChangeListener {
public void onRefresh();

public void onLoad();
}

private OnRefChangeListener mOnRefChangeListener;

public void setOnRefChangeListener(OnRefChangeListener onRefChangeListener) {
mOnRefChangeListener = onRefChangeListener;
}

/**
* 加载更多的监听器
*
* @author mrsimple
*/
public static interface OnLoadListener {
public void onLoad();
}
}

使用

<cn.mvp.test.RefreshLayout
android:id="@+id/swipe_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</cn.mvp.test.RefreshLayout>final List<String> datas = new ArrayList<String>();
for (int i = 0; i < 20; i++) {
datas.add("item - " + i);
}

// 构造适配器
BaseAdapter adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, datas);
// 获取listview实例
ListView listView = (ListView) findViewById(R.id.listview);
listView.setAdapter(adapter);
// 获取RefreshLayout实例
RefreshLayout myRefreshListView = (RefreshLayout) findViewById(R.id.swipe_layout);

// 设置下拉刷新时的颜色值,颜色值需要定义在xml中
// myRefreshListView.setColorScheme(R.color.umeng_comm_text_topic_light_color,
// R.color.umeng_comm_yellow, R.color.umeng_comm_green,
// R.color.umeng_comm_linked_text);
// 设置下拉刷新监听器
myRefreshListView.setOnRefChangeListener(new RefreshLayout.OnRefChangeListener() {
@Override
public void onRefresh() {
XLog.showArgsInfo("refresh");
myRefreshListView.postDelayed(new Runnable() {
@Override
public void run() {
// 更新数据
datas.add(new Date().toGMTString());
adapter.notifyDataSetChanged();
// 更新完后调用该方法结束刷新
myRefreshListView.setRefreshing(false);
}
}, 3000);
}

@Override
public void onLoad() {

XLog.showArgsInfo("load");

myRefreshListView.postDelayed(new Runnable() {

@Override
public void run() {
// datas.add(new Date().toGMTString());
// adapter.notifyDataSetChanged();
// 加载完后调用该方法
myRefreshListView.setLoading(true);
}
}, 1500);
}
});