一、ListView加腳佈局java
頭佈局initHeaderView,在onTouchEvent事件中進行顯示隱藏頭佈局切換android
腳佈局initFooterView,實現接口OnScrollListener,重寫接口方法onScrollStateChanged onScroll 進行顯示隱藏腳佈局切換緩存
添加標記isLoadingMore,是否正在加載數據,防止屢次滑動重複加載數據網絡
<?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:gravity="center" android:orientation="horizontal" > <ProgressBar android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:indeterminateDrawable="@drawable/custom_progress" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="5dp" android:text="加載中..." android:textColor="#f00" android:textSize="17sp" /> </LinearLayout>
import java.text.SimpleDateFormat; import java.util.Date; import android.content.Context; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.animation.Animation; import android.view.animation.RotateAnimation; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.AdapterView; import android.widget.ImageView; import android.widget.ListView; import android.widget.ProgressBar; import android.widget.TextView; import com.itheima.zhsh66.R; /** * 下拉刷新的listview * */ public class RefreshListView extends ListView implements OnScrollListener, android.widget.AdapterView.OnItemClickListener { private static final int STATE_PULL_TO_REFRESH = 1;// 下拉刷新 private static final int STATE_RELEASE_TO_REFRESH = 2;// 鬆開刷新 private static final int STATE_REFRESHING = 3;// 正在刷新 // 下拉刷新頭佈局 private View mHeaderView; // 頭佈局高度 private int mHeaderViewHeight; // 腳佈局 private View mFooterView; private int mFooterViewHeight; private int startY = -1; // 當前下拉刷新的狀態 private int mCurrentState = STATE_PULL_TO_REFRESH;// 默認是下拉刷新 private TextView tvTitle; private ImageView ivArrow; private ProgressBar pbLoading; private TextView tvTime; private RotateAnimation animUp;// 箭頭向上動畫 private RotateAnimation animDown;// 箭頭向下動畫 private boolean isLoadingMore;// 標記是否正在加載更多 public RefreshListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initHeaderView(); initFooterView(); } public RefreshListView(Context context, AttributeSet attrs) { super(context, attrs); initHeaderView(); initFooterView(); } public RefreshListView(Context context) { super(context); initHeaderView(); initFooterView(); } /** * 初始化頭佈局 */ private void initHeaderView() { mHeaderView = View.inflate(getContext(), R.layout.list_refresh_header, null); this.addHeaderView(mHeaderView);// 添加頭佈局 // 隱藏頭佈局(1, 獲取頭佈局高度, 2.設置負paddingTop,佈局就會往上走) // int height = mHeaderView.getHeight();//此處沒法獲取高度,由於佈局尚未繪製完成 // 繪製以前就要獲取佈局高度 mHeaderView.measure(0, 0);// 手動測量佈局 mHeaderViewHeight = mHeaderView.getMeasuredHeight();// 測量以後的高度 // 隱藏頭佈局 mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0); tvTitle = (TextView) mHeaderView.findViewById(R.id.tv_title); ivArrow = (ImageView) mHeaderView.findViewById(R.id.iv_arrow); pbLoading = (ProgressBar) mHeaderView.findViewById(R.id.pb_loading); tvTime = (TextView) mHeaderView.findViewById(R.id.tv_time); initAnim(); setCurrentTime();// 設置初始時間 } /** * 初始化腳佈局 */ private void initFooterView() { mFooterView = View.inflate(getContext(), R.layout.list_refresh_footer, null); this.addFooterView(mFooterView); mFooterView.measure(0, 0); mFooterViewHeight = mFooterView.getMeasuredHeight(); // 隱藏腳佈局 mFooterView.setPadding(0, -mFooterViewHeight, 0, 0); // 設置滑動監聽 this.setOnScrollListener(this); } @Override public boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: startY = (int) ev.getY(); break; case MotionEvent.ACTION_MOVE: if (startY == -1) {// 若是用戶按住頭條新聞向下滑動, 會致使listview沒法拿到ACTION_DOWN, // 此時要從新獲取startY startY = (int) ev.getY(); } // 若是當前正在刷新, 什麼都不作了 if (mCurrentState == STATE_REFRESHING) { break; } int endY = (int) ev.getY(); int dy = endY - startY; if (dy > 0 && getFirstVisiblePosition() == 0) {// 向下滑動&當前顯示的是第一個item,才容許下拉刷新 int paddingTop = dy - mHeaderViewHeight;// 計算當前的paddingtop值 // 根據padding切換狀態 if (paddingTop >= 0 && mCurrentState != STATE_RELEASE_TO_REFRESH) { // 切換到鬆開刷新 mCurrentState = STATE_RELEASE_TO_REFRESH; refreshState(); } else if (paddingTop < 0 && mCurrentState != STATE_PULL_TO_REFRESH) { // 切換到下拉刷新 mCurrentState = STATE_PULL_TO_REFRESH; refreshState(); } mHeaderView.setPadding(0, paddingTop, 0, 0);// 從新設置頭佈局padding return true; } break; case MotionEvent.ACTION_UP: startY = -1;// 起始座標歸零 if (mCurrentState == STATE_RELEASE_TO_REFRESH) { // 若是當前是鬆開刷新, 就要切換爲正在刷新 mCurrentState = STATE_REFRESHING; // 顯示頭佈局 mHeaderView.setPadding(0, 0, 0, 0); refreshState(); // 下拉刷新回調 if (mListener != null) { mListener.onRefresh(); } } else if (mCurrentState == STATE_PULL_TO_REFRESH) { // 隱藏頭佈局 mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0); } break; default: break; } return super.onTouchEvent(ev); } /** * 初始化箭頭動畫 */ private void initAnim() { animUp = new RotateAnimation(0, -180, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); animUp.setDuration(500); animUp.setFillAfter(true);// 保持狀態 animDown = new RotateAnimation(-180, 0, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); animDown.setDuration(500); animDown.setFillAfter(true);// 保持狀態 } /** * 根據當前狀態刷新界面 */ private void refreshState() { switch (mCurrentState) { case STATE_PULL_TO_REFRESH: tvTitle.setText("下拉刷新"); // 箭頭向下移動 ivArrow.startAnimation(animDown); // 隱藏進度條 pbLoading.setVisibility(View.INVISIBLE); ivArrow.setVisibility(View.VISIBLE); break; case STATE_RELEASE_TO_REFRESH: tvTitle.setText("鬆開刷新"); // 箭頭向上移動 ivArrow.startAnimation(animUp); // 隱藏進度條 pbLoading.setVisibility(View.INVISIBLE); ivArrow.setVisibility(View.VISIBLE); break; case STATE_REFRESHING: tvTitle.setText("正在刷新..."); pbLoading.setVisibility(View.VISIBLE); ivArrow.clearAnimation();// 必須清除動畫,才能隱藏控件 ivArrow.setVisibility(View.INVISIBLE); break; default: break; } } private OnRefreshListener mListener; public void setOnRefreshListener(OnRefreshListener listener) { mListener = listener; } /** * 設置上次刷新時間 */ private void setCurrentTime() { // 08:10 8:10 1 SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// HH表示24小時制 String time = format.format(new Date()); tvTime.setText(time); } // 刷新完成 public void onRefreshComplete(boolean success) { if (!isLoadingMore) { // 隱藏頭佈局 mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0); mCurrentState = STATE_PULL_TO_REFRESH; // 隱藏進度條 pbLoading.setVisibility(View.INVISIBLE); ivArrow.setVisibility(View.VISIBLE); tvTitle.setText("下拉刷新"); // 刷新失敗,不須要更新時間 if (success) { setCurrentTime(); } } else { // 隱藏腳佈局 mFooterView.setPadding(0, -mFooterViewHeight, 0, 0); isLoadingMore = false; } } public interface OnRefreshListener { // 下拉刷新的回調 public void onRefresh(); // 加載更多的回調 public void loadMore(); } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { if (scrollState == SCROLL_STATE_IDLE) { int lastVisiblePosition = getLastVisiblePosition();// 當前界面顯示的最後一個item的位置 if (lastVisiblePosition >= getCount() - 1 && !isLoadingMore) { isLoadingMore = true; // System.out.println("到底了"); // 加載更多了....(到底了) // 顯示腳佈局 mFooterView.setPadding(0, 0, 0, 0); // listview設置當前要展現的item的位置 setSelection(getCount() - 1);// 跳到加載更多item的位置去展現 if (mListener != null) { mListener.loadMore(); } } } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } private OnItemClickListener mItemClickListener; // 重寫item點擊方法 @Override public void setOnItemClickListener( android.widget.AdapterView.OnItemClickListener listener) { mItemClickListener = listener; super.setOnItemClickListener(this);// 將點擊事件設置給當前的RefreshListView } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { if (mItemClickListener != null) { mItemClickListener.onItemClick(parent, view, position - getHeaderViewsCount(), id); } } }
定義對外加載數據的回調接口app
public interface OnRefreshListener {
// 下拉刷新的回調
public void onRefresh();dom
// 加載更多的回調
public void loadMore();
}ide
listview設置當前要展現的item的位置
setSelection(getCount() - 1);// 跳到加載更多item的位置去展現工具
二、網絡數據分頁請求加載,在JSON數據中定義下一頁數據的URL,當爲空時表示數據加載完成佈局
爲了避免覆蓋已經下載的數據,能夠在原數據的基礎上追加數據動畫
protected void processResult(String result, boolean isMore)
.......else {
// 加載更多
ArrayList<News> moreData = mNewsTabData.data.news;
mNewsList.addAll(moreData);// 追加數據
mNewsAdapter.notifyDataSetChanged();// 刷新listview
}
import java.util.ArrayList; import android.app.Activity; import android.content.Intent; import android.graphics.Color; import android.os.Handler; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.text.TextUtils; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import android.widget.TextView; import android.widget.Toast; import com.google.gson.Gson; import com.itheima.zhsh66.NewsDetailActivity; import com.itheima.zhsh66.R; import com.itheima.zhsh66.base.BaseMenuDetailPager; import com.itheima.zhsh66.domain.NewsData; import com.itheima.zhsh66.domain.NewsData.News; import com.itheima.zhsh66.domain.NewsData.TopNews; import com.itheima.zhsh66.domain.NewsMenuData.NewsTabData; import com.itheima.zhsh66.global.Constants; import com.itheima.zhsh66.utils.CacheUtils; import com.itheima.zhsh66.utils.PrefUtils; import com.itheima.zhsh66.view.HorizontalScrollViewPager; import com.itheima.zhsh66.view.RefreshListView; import com.itheima.zhsh66.view.RefreshListView.OnRefreshListener; import com.lidroid.xutils.BitmapUtils; import com.lidroid.xutils.HttpUtils; import com.lidroid.xutils.ViewUtils; import com.lidroid.xutils.exception.HttpException; import com.lidroid.xutils.http.ResponseInfo; import com.lidroid.xutils.http.callback.RequestCallBack; import com.lidroid.xutils.http.client.HttpRequest.HttpMethod; import com.lidroid.xutils.view.annotation.ViewInject; import com.viewpagerindicator.CirclePageIndicator; /** * 12個頁籤的頁面對象 * */ public class TabDetailPager extends BaseMenuDetailPager { // 頁籤分類的網絡信息 private NewsTabData mTabData; // 網絡返回的新聞列表數據 private NewsData mNewsTabData; // 加載新聞列表的url private String mUrl; // 頭條新聞的網絡數據 private ArrayList<TopNews> mTopNewsList; // 頭條新聞的數據適配器 private TopNewsAdapter mTopNewsAdapter; // 新聞列表的集合 private ArrayList<News> mNewsList; private NewsAdapter mNewsAdapter; @ViewInject(R.id.vp_tab_detail) private HorizontalScrollViewPager mViewPager; @ViewInject(R.id.lv_tab_detail) private RefreshListView lvList; @ViewInject(R.id.indicator) private CirclePageIndicator mIndicator; @ViewInject(R.id.tv_title) private TextView tvTopNewsTitle; private String mMoreUrl;// 下一頁的連接 private Handler mHandler = null; public TabDetailPager(Activity activity, NewsTabData tabData) { super(activity); mTabData = tabData; mUrl = Constants.SERVER_URL + mTabData.url; } @Override public View initView() { View view = View.inflate(mActivity, R.layout.pager_tab_detail, null); ViewUtils.inject(this, view); View header = View.inflate(mActivity, R.layout.list_header_topnews, null); ViewUtils.inject(this, header);// 必須也將頭佈局注入到ViewUtils // 給listview添加頭佈局 lvList.addHeaderView(header); // 設置下拉刷新監聽 lvList.setOnRefreshListener(new OnRefreshListener() { @Override public void onRefresh() { // 從網絡加載數據 getDataFromServer(); } @Override public void loadMore() { // 加載更多數據 if (mMoreUrl != null) { System.out.println("加載下一頁數據..."); getMoreDataFromServer(); } else { lvList.onRefreshComplete(true);// 收起加載更多佈局 Toast.makeText(mActivity, "沒有更多數據了", Toast.LENGTH_SHORT) .show(); } } }); lvList.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { System.out.println("pos:" + position); News news = mNewsList.get(position); // 當前點擊的item的標題顏色置灰 TextView tvTitle = (TextView) view.findViewById(R.id.tv_title); tvTitle.setTextColor(Color.GRAY); // 將已讀狀態持久化到本地 // key: read_ids; value: 1324,1325,1326 String readIds = PrefUtils.getString("read_ids", "", mActivity); if (!readIds.contains(news.id)) {// 之前沒有添加過,才添加進來 readIds = readIds + news.id + ",";// 1324,1325, PrefUtils.putString("read_ids", readIds, mActivity); } // 跳到詳情頁 Intent intent = new Intent(mActivity, NewsDetailActivity.class); intent.putExtra("url", news.url); mActivity.startActivity(intent); } }); return view; } @Override public void initData() { String cache = CacheUtils.getCache(mUrl, mActivity); if (!TextUtils.isEmpty(cache)) { processResult(cache, false); } getDataFromServer(); } private void getDataFromServer() { HttpUtils utils = new HttpUtils(); utils.send(HttpMethod.GET, mUrl, new RequestCallBack<String>() { @Override public void onSuccess(ResponseInfo<String> responseInfo) { String result = responseInfo.result; processResult(result, false); System.out.println("訪問網絡成功!!!"); CacheUtils.setCache(mUrl, result, mActivity); // 收起下拉刷新控件 lvList.onRefreshComplete(true); } @Override public void onFailure(HttpException error, String msg) { // 收起下拉刷新控件 lvList.onRefreshComplete(false); error.printStackTrace(); Toast.makeText(mActivity, msg, Toast.LENGTH_SHORT).show(); } }); } /** * 加載更多數據 */ protected void getMoreDataFromServer() { HttpUtils utils = new HttpUtils(); utils.send(HttpMethod.GET, mMoreUrl, new RequestCallBack<String>() { @Override public void onSuccess(ResponseInfo<String> responseInfo) { String result = responseInfo.result; processResult(result, true); // 收起加載更多佈局 lvList.onRefreshComplete(true); } @Override public void onFailure(HttpException error, String msg) { error.printStackTrace(); Toast.makeText(mActivity, msg, Toast.LENGTH_SHORT).show(); // 收起加載更多佈局 lvList.onRefreshComplete(false); } }); } protected void processResult(String result, boolean isMore) { Gson gson = new Gson(); mNewsTabData = gson.fromJson(result, NewsData.class); if (!TextUtils.isEmpty(mNewsTabData.data.more)) { // 初始化下一頁連接地址 mMoreUrl = Constants.SERVER_URL + mNewsTabData.data.more; } else { // 沒有下一頁了 mMoreUrl = null; } if (!isMore) { // 初始化頭條新聞 mTopNewsList = mNewsTabData.data.topnews; if (mTopNewsList != null) { mTopNewsAdapter = new TopNewsAdapter(); mViewPager.setAdapter(mTopNewsAdapter); mIndicator.setViewPager(mViewPager);// 將指示器和viewpager綁定 mIndicator.setSnap(true);// 快照模式 mIndicator.setOnPageChangeListener(new OnPageChangeListener() { @Override public void onPageSelected(int position) { //System.out.println("position:" + position); TopNews topNews = mTopNewsList.get(position); tvTopNewsTitle.setText(topNews.title); } @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageScrollStateChanged(int state) { } }); mIndicator.onPageSelected(0);// 將小圓點位置歸零, 解決它會在頁面銷燬時仍記錄上次位置的bug tvTopNewsTitle.setText(mTopNewsList.get(0).title);// 初始化第一頁標題 } // 初始化新聞列表 mNewsList = mNewsTabData.data.news; if (mNewsList != null) { mNewsAdapter = new NewsAdapter(); lvList.setAdapter(mNewsAdapter); } if (mHandler == null) { mHandler = new Handler() { public void handleMessage(android.os.Message msg) { int currentItem = mViewPager.getCurrentItem(); if (currentItem < mTopNewsList.size() - 1) { currentItem++; } else { currentItem = 0; } mViewPager.setCurrentItem(currentItem); mHandler.sendEmptyMessageDelayed(0, 2000); }; }; // 延時2秒切換廣告條 mHandler.sendEmptyMessageDelayed(0, 2000); mViewPager.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: System.out.println("ACTION_DOWN"); // 刪除全部消息 mHandler.removeCallbacksAndMessages(null); break; case MotionEvent.ACTION_CANCEL:// 事件取消(當按下後,而後移動下拉刷新,致使擡起後沒法響應ACTION_UP, // 但此時會響應ACTION_CANCEL,也須要繼續播放輪播條) case MotionEvent.ACTION_UP: // 延時2秒切換廣告條 mHandler.sendEmptyMessageDelayed(0, 2000); break; default: break; } return false; } }); } } else { // 加載更多 ArrayList<News> moreData = mNewsTabData.data.news; mNewsList.addAll(moreData);// 追加數據 mNewsAdapter.notifyDataSetChanged();// 刷新listview } } class TopNewsAdapter extends PagerAdapter { BitmapUtils mBitmapUtils; public TopNewsAdapter() { // 初始化xutils中的加載圖片的工具 mBitmapUtils = new BitmapUtils(mActivity); // 設置默認加載圖片 mBitmapUtils .configDefaultLoadingImage(R.drawable.topnews_item_default); } @Override public int getCount() { return mTopNewsList.size(); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } @Override public Object instantiateItem(ViewGroup container, int position) { ImageView view = new ImageView(mActivity); view.setScaleType(ScaleType.FIT_XY);// 設置圖片填充效果, 表示填充父窗體 // 獲取圖片連接, 使用連接下載圖片, 將圖片設置給ImageView, 考慮內存溢出問題, 圖片本地緩存 mBitmapUtils.display(view, mTopNewsList.get(position).topimage); container.addView(view); return view; } @Override public void destroyItem(ViewGroup container, int position, Object object) { container.removeView((View) object); } } class NewsAdapter extends BaseAdapter { public BitmapUtils mBitmapUtils; public NewsAdapter() { mBitmapUtils = new BitmapUtils(mActivity); mBitmapUtils .configDefaultLoadingImage(R.drawable.pic_item_list_default); } @Override public int getCount() { return mNewsList.size(); } @Override public News getItem(int position) { return mNewsList.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder; if (convertView == null) { convertView = View.inflate(mActivity, R.layout.list_item_news, null); holder = new ViewHolder(); holder.tvTitle = (TextView) convertView .findViewById(R.id.tv_title); holder.tvDate = (TextView) convertView .findViewById(R.id.tv_date); holder.ivIcon = (ImageView) convertView .findViewById(R.id.iv_icon); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } News news = getItem(position); holder.tvTitle.setText(news.title); holder.tvDate.setText(news.pubdate); mBitmapUtils.display(holder.ivIcon, news.listimage); // 標記已讀和未讀 String readIds = PrefUtils.getString("read_ids", "", mActivity); if (readIds.contains(news.id)) { // 已讀 holder.tvTitle.setTextColor(Color.GRAY); } else { // 未讀 holder.tvTitle.setTextColor(Color.BLACK); } return convertView; } } static class ViewHolder { public TextView tvTitle; public TextView tvDate; public ImageView ivIcon; } }