(Android)五分鐘讓你輕鬆學會下拉重新整理和上拉載入更多
阿新 • • 發佈：2019-01-23
分享一個谷歌自帶的下拉重新整理和上拉載入更多例子:
先看效果圖:
/** * 繼承自SwipeRefreshLayout,從而實現滑動到底部時上拉載入更多的功能. */ public class RefreshLayout extends SwipeRefreshLayout implements OnScrollListener { /** * 滑動到最下面時的上拉操作 */ private int mTouchSlop; /** * listview例項 */ private ListView mListView; /** * 上拉監聽器, 到了最底部的上拉載入操作 */ private OnLoadListener mOnLoadListener; /** * ListView的載入中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; /** * 是否在載入中 ( 上拉載入更多 ) */ 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物件 if (mListView == null) { getListView(); } } /** * 獲取ListView物件 */ private void getListView() { int childs = getChildCount(); if (childs > 0) { View childView = getChildAt(0); if (childView instanceof ListView) { mListView = (ListView) childView; // 設定滾動監聽器給ListView, 使得滾動的情況下也可以自動載入 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); } /** * 是否可以載入更多, 條件是到了最底部, listview不在載入中, 且為上拉操作. * * @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) { // 設定狀態 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載入更多 if (canLoad()) { loadData(); } } /** * 設定重新整理 */ 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(); } } } /** * 載入更多的監聽器 */ public static interface OnLoadListener { public void onLoad(); } }
自定義介面卡
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(); /*設定自動重新整理 swipeLayout.setRefreshing(true); 在 setRefreshing(true)並沒有觸發onRefresh的,須要手動呼叫一次 */ // 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); } /** * 新增資料 */ 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+"預設"); map.put("itemText", i+"預設"); list.add(map); } listView = (ListView) findViewById(R.id.list); listView.addHeaderView(header); adapter = new MyAdapter(this, list); listView.setAdapter(adapter); } /** * 設定監聽 */ private void setListener() { swipeLayout.setOnRefreshListener(this); swipeLayout.setOnLoadListener(this); } /** * 上拉重新整理 */ @Override public void onRefresh() { swipeLayout.postDelayed(new Runnable() { @Override public void run() { // 更新資料 更新完後呼叫該方法結束重新整理 list.clear(); for (int i = 0; i < 8; i++) { HashMap<String, String> map = new HashMap<String, String>(); map.put("itemImage", i+"重新整理"); map.put("itemText", i+"重新整理"); list.add(map); } adapter.notifyDataSetChanged(); swipeLayout.setRefreshing(false); } }, 2000); } /** * 載入更多 */ @Override public void onLoad() { swipeLayout.postDelayed(new Runnable() { @Override public void run() { // 更新資料 更新完後呼叫該方法結束重新整理 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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