大家好我遇到问题，实现双击。那么我实现了ongestureListener和我有gesturedetector，但我不知道哪里出了问题，这是我的code：

hi guys i'm having problems with implementing the double tap. Well i implemented the ongestureListener and i had the gesturedetector, but i'm not sure where is the problem, here is my code:

 public class home extends TabActivity implements OnGestureListener {
    /** Called when the activity is first created. */

 private EditText queryText;
 private ResultsAdapter m_adapter;
 private ProgressDialog pd;
 final Handler h = new Handler();
 private TabHost mTabHost;
 private ArrayList<SearchItem> sResultsArr = new ArrayList<SearchItem>();
 private String queryStr;
 private JSONObject searchResponse;
 private GestureDetector gestureScanner;

 final Runnable mUpdateResults = new Runnable() {
        public void run() {
         updateListUi();
        }
    };

 @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button search = (Button)findViewById(R.id.search);
        Button testButt = (Button)findViewById(R.id.testbutt);
        queryText = (EditText)findViewById(R.id.query);
        ListView lvr = (ListView)findViewById(R.id.search_results);

      //initialise the arrayAdapter
        this.m_adapter = new ResultsAdapter(home.this, R.layout.listrow, sResultsArr);
        lvr.setAdapter(this.m_adapter);
        lvr.setOnItemClickListener(new OnItemClickListener(){
   @Override
   public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
     long arg3) {
    // TODO Auto-generated method stub
         pd = ProgressDialog.show(home.this, null,"Loading products from server", true, false);

   }

        });
        gestureScanner = new GestureDetector(this,this);
        gestureScanner.setOnDoubleTapListener(new OnDoubleTapListener(){ 
            public boolean onDoubleTap(MotionEvent e) { 
                 //viewA.setText("-" + "onDoubleTap" + "-"); 
         pd = ProgressDialog.show(home.this, null,"Loading products from server", true, false);

                 return false; 
            } 
            public boolean onDoubleTapEvent(MotionEvent e) { 
                // viewA.setText("-" + "onDoubleTapEvent" + "-"); 
                 return false; 
            } 
            public boolean onSingleTapConfirmed(MotionEvent e) { 
                 //viewA.setText("-" + "onSingleTapConfirmed" + "-"); 
                 return false; 
            } 

     });


        //initialise tab contents
        mTabHost = getTabHost();
        mTabHost.addTab(mTabHost.newTabSpec("tab1").setIndicator("Home").setContent(R.id.homepage));
        mTabHost.addTab(mTabHost.newTabSpec("tab2").setIndicator("Search Results").setContent(R.id.tab2));
        mTabHost.setCurrentTab(0);

        //sets the respective listeners
        testButt.setOnClickListener(new View.OnClickListener() {
        public void onClick(View arg0) {

         if(mTabHost.getTabWidget().getVisibility()==View.GONE){
          mTabHost.getTabWidget().setVisibility(View.VISIBLE);
         }
         else{
          mTabHost.getTabWidget().setVisibility(View.GONE);
         }
        }
     });

        search.setOnClickListener(new View.OnClickListener() {
        public void onClick(View arg0) {
         sResultsArr.clear();
         queryStr = "http://rose.mosuma.com/mobile?query=" + queryText.getText().toString();
         pd = ProgressDialog.show(home.this, null,"Loading products from server", true, false);
         goSearch();
      }
     });
    }

 //updates the listUI whenever after receiving the response from the server
 public void updateListUi(){  
    if(sResultsArr.size() > 0){

       }

    try{
     String ptypename;
     int count;
     LinearLayout ptypebar = (LinearLayout)findViewById(R.id.productCat);
     ptypebar.removeAllViews();
     JSONArray ptypes = searchResponse.getJSONArray("ptypes"); 
     for(int index =0;index < ptypes.length();index++){
      JSONObject ptype = ptypes.getJSONObject(index);
      count = ptype.getInt("count");      
      ptypename = ptype.getString("ptypename"); 

      //add into tab 2's UI

      //ImageView icon = new ImageView(this);
      TextView t = new TextView(home.this);
      t.setText(ptypename + " (" + count + ")");
      ptypebar.addView(t);
     }
    }
    catch(JSONException e){

    }
   //if(m_adapter.getItems() != sResultsArr){
    ArrayList<SearchItem> a  = m_adapter.getItems(); 
    a = sResultsArr;
   //}
      m_adapter.notifyDataSetChanged();
     pd.dismiss();
 }

 public void goSearch(){
  mTabHost.setCurrentTab(1);

  //separate thread for making http request and updating the arraylist
  Thread t = new Thread() {
           public void run() {

            searchResponse = sendSearchQuery(queryStr);
            try{
             JSONArray results = searchResponse.getJSONArray("results");

             //this is stupid. i probably have to see how to make a json adapter
             for(int index =0;index < results.length();index++){

              JSONObject product = results.getJSONObject(index);

              //gets the searched products from the json object
              URL imgUrl =  new URL(product.getString("image"));
              String productname = product.getString("productname");
              String ptypename = product.getString("ptypename");
              int pid = product.getInt("pid");
              int positive = product.getInt("pos");
              int negative = product.getInt("neg");
              int neutral = product.getInt("neu");


              SearchItem item  = new SearchItem(imgUrl,productname,ptypename,neutral,positive,negative,pid);
              sResultsArr.add(item);
             }
            }
            catch(JSONException e){

            }
            catch(Exception e){

               }
            //returns back to UI therad
            h.post(mUpdateResults);
           }
       };
       t.start();
 }

 //sends a request with qry as URL
 //and receives back a JSONobject as response
 public JSONObject sendSearchQuery(String qry){
  HttpRequest r = new HttpRequest();
  JSONObject response = r.sendHttpRequest(qry);  
  return response;
 }

 @Override
 public boolean onDown(MotionEvent arg0) {
      return gestureScanner.onTouchEvent(arg0); 
 }

 @Override
 public boolean onFling(MotionEvent arg0, MotionEvent arg1, float arg2,
   float arg3) {
  // TODO Auto-generated method stub
  return false;
 }

 @Override
 public void onLongPress(MotionEvent arg0) {
  // TODO Auto-generated method stub

 }

 @Override
 public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
   float arg3) {
  // TODO Auto-generated method stub
  return false;
 }

 @Override
 public void onShowPress(MotionEvent arg0) {
  // TODO Auto-generated method stub

 }

 @Override
 public boolean onSingleTapUp(MotionEvent arg0) {
  // TODO Auto-generated method stub
  return false;
 }

呵呵，另外一个问题，如果我的列表视图有一个onItemClickListener，可以单的android水龙头或双击的检测呢？

Oh, another question, if my listview has an onItemClickListener, can android detect between single tap or double tap for it?

推荐答案

你为什么不使用长preSS？或者，您使用已经别的东西？在长期接触的优点双触摸：

Why aren't you using a Long Press? Or are you using that already for something else? The advantages over a long touch over a double touch:

长preSS是在UI准则特别建议的互动，双触摸没有。 这就是用户所期望的;用户可能无法找到一个双触摸动作，因为他们不会去寻找它 在它已经handled在API 。 实施两次触摸会影响处理单个触摸的，因为你将不得不等待，看看每一个触控变成双触摸，然后才能对其进行处理。 Long Press is a recommeded interaction in the UI Guidelines, double touch is not. It's what users expect; a user might not find a double touch action as they won't go looking for it It's already handled in the API. Implementing Double Touch will affect handling of single touches, because you'll have to wait to see if every single touch turns into a double touch before you can process it.