自動輪播,類似字幕或圖片自動滾動播放
阿新 • • 發佈:2019-01-24
功能:ListView沒隔一段時間自動滾動一段距離,當滾動到底部時,又從頭開始顯示,類似於原始資料為0123,而滾動起來則是012301230123...一直重複顯示,這樣就達到了資訊輪播的功能。
本功能採用擴充套件ListView來實現的,
介面卡public class AutoCircleScrollListview extends ListView implements OnScrollListener{ public final static int REFRESH_TIMES=1000;//滾動頻率,單位毫秒 public final static int SCROLL_DISTANCE=10;//每次滾動距離,單位是pixels private Handler mHandler=new Handler(); private RefreshRunnable mRefreshRunnable; private boolean isStop=false; public AutoCircleScrollListview(Context context) { super(context); init(); } public AutoCircleScrollListview(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init(){ //設定滾動監聽器 setOnScrollListener(this); //不顯示滾動條 setVerticalScrollBarEnabled(false); setHorizontalScrollBarEnabled(false); //不可觸控 setEnabled(false); } /** * 開始滾動 */ public void startRoll(){ isStop=false; setSelection(getCount()/AutoCircleScrollAdapter.REPEAT_TIMES); if(mRefreshRunnable==null){ mRefreshRunnable=new RefreshRunnable(); } mHandler.postDelayed(mRefreshRunnable, REFRESH_TIMES); } /** * 停止滾動 */ private void stopRoll(){ isStop=true; if(mRefreshRunnable!=null){ mHandler.removeCallbacks(mRefreshRunnable); } mRefreshRunnable=null; } /** * * @Create_date 2014-10-24 下午1:02:50 * @TODO */ private class RefreshRunnable implements Runnable{ @Override public void run() { if(!isStop){ smoothScrollBy(SCROLL_DISTANCE, 0); mHandler.postDelayed(this, REFRESH_TIMES); } } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { if (firstVisibleItem <= 2) {//到頂部 int listSize=getCount()/AutoCircleScrollAdapter.REPEAT_TIMES; setSelection(listSize + 2); } else if (firstVisibleItem + visibleItemCount > getCount() - 2) {//到底部 int listSize=getCount()/AutoCircleScrollAdapter.REPEAT_TIMES; setSelection(firstVisibleItem - listSize); } } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { } public void onStop(){ stopRoll(); } public void onResume(){ if(isStop){ startRoll(); } } public void onDestroy(){ stopRoll(); } }
public class AutoCircleScrollAdapter extends BaseAdapter { /** * 迴圈展示次數,最理想的值為3 */ public static final int REPEAT_TIMES = 3; private List<Map<String, Object>> mDatas; private int mLayoutId; private String[] mFrom; private int[] mTo; private Context mContext; public AutoCircleScrollAdapter(Context context, int resLayoutId, String[] from, int[] to, List<Map<String, Object>> datas) { this.mContext = context; this.mDatas = datas; this.mLayoutId = resLayoutId; this.mFrom = from; this.mTo = to; } /** * 將資料迴圈展示三遍 */ @Override public int getCount() { if (mDatas != null) { return mDatas.size() * REPEAT_TIMES; } return 0; } @Override public Object getItem(int arg0) { return mDatas.get(arg0 % mDatas.size()); } @Override public long getItemId(int arg0) { return arg0 % mDatas.size(); } @Override public View getView(int postition, View convertView, ViewGroup arg2) { View v; if (convertView == null) { v = LayoutInflater.from(mContext).inflate(mLayoutId, null); } else { v = convertView; } bindView(v, postition); return v; } private void bindView(View view, int position) { final Map<String, Object> dataSet = mDatas.get(position%mDatas.size()); if (dataSet == null) { return; } final String[] from = mFrom; final int[] to = mTo; final int count = to.length; for (int i = 0; i < count; i++) { final View v = view.findViewById(to[i]); if (v != null) { String clzzName = v.getClass().getSimpleName(); if (clzzName.equals("TextView")) {// 設定文字框內容 final Object data = dataSet.get(from[i]); String text = data == null ? "" : data.toString(); if (text == null) { text = ""; } ((TextView) v).setText(text); }else {//在此可以拓展自己的view } } } } }
使用
public class MainActivity extends Activity { AutoCircleScrollListview mAutoCircleScrollListview; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mAutoCircleScrollListview=(AutoCircleScrollListview) findViewById(R.id.lv_autoCircleScroll); List<Map<String, Object>> datas=new ArrayList<Map<String,Object>>(); for (int i = 0; i < 5; i++) { Map<String, Object> map=new HashMap<String, Object>(); map.put("txt_tire_index", ""+i); map.put("txt_pressure_value", "1"+i+".0"); map.put("txt_tmper_valude", "01"+i+"'C"); datas.add(map); } AutoCircleScrollAdapter adapter=new AutoCircleScrollAdapter( this, R.layout.item_auto_circle_scroll_listview, new String[]{"txt_tire_index","txt_pressure_value","txt_tmper_valude"}, new int[]{R.id.txt_tire_index,R.id.txt_pressure_value,R.id.txt_tmper_valude}, datas); mAutoCircleScrollListview.setAdapter(adapter); mAutoCircleScrollListview.startRoll(); } @Override protected void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); mAutoCircleScrollListview.onDestroy(); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); mAutoCircleScrollListview.onResume(); } @Override protected void onStop() { // TODO Auto-generated method stub super.onStop(); mAutoCircleScrollListview.onStop(); } }
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