分享一個谷歌自帶的下拉刷新和上拉加載更多例子:
先看效果圖:
/**
* 繼承自SwipeRefreshLayout,從而實現滑動到底部時上拉加載更多的功能.
*/
public class RefreshLayout extends SwipeRefreshLayout implements
OnScrollListener {
/**
* 滑動到最下面時的上拉操作
*/
private int mTouchSlop;
/**
* listview實例
*/
private ListView mListView;
/**
* 上拉監聽器, 到了最底部的上拉加載操作
*/
private OnLoadListener mOnLoadListener;
/**
* ListView的加載中footer
*/
private View mListViewFooter;
/**
* 按下時的y座標
*/
private int mYDown;
/**
* 擡起時的y座標, 與mYDown一起用於滑動到底部時判斷是上拉還是下拉
*/
private int mLastY;
/**
* 是否在加載中 ( 上拉加載更多 )
*/
private boolean isLoading = false;
/**
* @param context
*/
public RefreshLayout(Context context) {
this(context, null);
}
@SuppressLint("InflateParams")
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對象
if (mListView == null) {
getListView();
}
}
/**
* 獲取ListView對象
*/
private void getListView() {
int childs = getChildCount();
if (childs > 0) {
View childView = getChildAt(0);
if (childView instanceof ListView) {
mListView = (ListView) childView;
// 設置滾動監聽器給ListView, 使得滾動的情況下也可以自動加載
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:
// 移動
mLastY = (int) event.getRawY();
break;
case MotionEvent.ACTION_UP:
// 擡起
if (canLoad()) {
loadData();
}
break;
default:
break;
}
return super.dispatchTouchEvent(event);
}
/**
* 是否可以加載更多, 條件是到了最底部, listview不在加載中, 且爲上拉操作.
*
* @return
*/
private boolean canLoad() {
return isBottom() && !isLoading && isPullUp();
}
/**
* 判斷是否到了最底部
*/
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.那麼執行onLoad方法
*/
private void loadData() {
if (mOnLoadListener != null) {
// 設置狀態
setLoading(true);
//
mOnLoadListener.onLoad();
}
}
/**
* @param loading
*/
public void setLoading(boolean loading) {
isLoading = loading;
if (isLoading) {
mListView.addFooterView(mListViewFooter);
} else {
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) {
// 滾動時到了最底部也可以加載更多
if (canLoad()) {
loadData();
}
}
/**
* 設置刷新
*/
public static void setRefreshing(SwipeRefreshLayout refreshLayout,
boolean refreshing, boolean notify) {
Class<? extends SwipeRefreshLayout> refreshLayoutClass = refreshLayout
.getClass();
if (refreshLayoutClass != null) {
try {
Method setRefreshing = refreshLayoutClass.getDeclaredMethod(
"setRefreshing", boolean.class, boolean.class);
setRefreshing.setAccessible(true);
setRefreshing.invoke(refreshLayout, refreshing, notify);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
/**
* 加載更多的監聽器
*/
public static interface OnLoadListener {
public void onLoad();
}
}
自定義適配器
public class MyAdapter extends BaseAdapter {
public ArrayList<HashMap<String, String>> list;
public Context context;
public LayoutInflater layoutInflater;
public MyAdapter(Context context, ArrayList<HashMap<String, String>> list) {
this.context = context;
this.list = list;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = null;
ViewHolder holder = null;
if (convertView == null) {
view = layoutInflater.inflate(R.layout.item, null);
holder = new ViewHolder();
holder.txt =(TextView) view.findViewById(R.id.textView1);
view.setTag(holder);
} else {
view = convertView;
holder = (ViewHolder) view.getTag();
}
holder.txt.setText(list.get(position).get("itemText"));
return view;
}
static class ViewHolder {
TextView txt;
}
}
新建一個Activity展示
public class MainActivity extends Activity implements OnRefreshListener,
OnLoadListener {
private RefreshLayout swipeLayout;
private ListView listView;
private MyAdapter adapter;
private ArrayList<HashMap<String, String>> list;
private View header;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
setData();
setListener();
/*設置自動刷新 swipeLayout.setRefreshing(true);
在 setRefreshing(true)並沒有觸發onRefresh的,須要手動調用一次
*/
// swipeLayout.post(new Thread(new Runnable() {
// @Override
// public void run() {
// swipeLayout.setRefreshing(true);
// }
// }));
// onRefresh();
}
/**
* 初始化佈局
*/
@SuppressLint({ "InlinedApi", "InflateParams" })
private void initView() {
header = getLayoutInflater().inflate(R.layout.header, null);
swipeLayout = (RefreshLayout) findViewById(R.id.swipe_container);
swipeLayout.setColorSchemeResources(R.color.color_bule2,R.color.color_bule,R.color.color_bule2,R.color.color_bule3);
}
/**
* 添加數據
*/
private void setData() {
list = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < 10; i++) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("itemImage", i+"默認");
map.put("itemText", i+"默認");
list.add(map);
}
listView = (ListView) findViewById(R.id.list);
listView.addHeaderView(header);
adapter = new MyAdapter(this, list);
listView.setAdapter(adapter);
}
/**
* 設置監聽
*/
private void setListener() {
swipeLayout.setOnRefreshListener(this);
swipeLayout.setOnLoadListener(this);
}
/**
* 上拉刷新
*/
@Override
public void onRefresh() {
swipeLayout.postDelayed(new Runnable() {
@Override
public void run() {
// 更新數據 更新完後調用該方法結束刷新
list.clear();
for (int i = 0; i < 8; i++) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("itemImage", i+"刷新");
map.put("itemText", i+"刷新");
list.add(map);
}
adapter.notifyDataSetChanged();
swipeLayout.setRefreshing(false);
}
}, 2000);
}
/**
* 加載更多
*/
@Override
public void onLoad() {
swipeLayout.postDelayed(new Runnable() {
@Override
public void run() {
// 更新數據 更新完後調用該方法結束刷新
swipeLayout.setLoading(false);
for (int i = 1; i < 10; i++) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("itemImage", i+"更多");
map.put("itemText", i+"更多");
list.add(map);
}
adapter.notifyDataSetChanged();
}
}, 2000);
}
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