Android-如何收聽imagebutton單擊？

Question

我已經在Google上搜索了很長時間，但是我不知道該怎么做。

我用一個包含3個textview（1個用於獲取數據）和2個imagebutton的項目填充listview

單擊第一個按鈕時，我想獲取第三個textview文本，這是到目前為止的代碼：

Search.java

 public class Search extends ListActivity {

    private TextView mTextView;
     private ListView mListView;
     private String query;
     private String queryencoded;
     private static Context mContext;

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

        mTextView = (TextView) findViewById(R.id.text);
        mListView = (ListView) findViewById(android.R.id.list);

        mContext = getApplicationContext();

        // Get the intent, verify the action and get the query
        Intent intent = getIntent();
        if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
          query = intent.getStringExtra(SearchManager.QUERY);
        try {
            queryencoded = URLEncoder.encode(query, "utf-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
          Log.w("myApp", "aaaaa");
          Toast.makeText(Search.this, (query), Toast.LENGTH_LONG).show();


          mTextView.setText("testing connexion");

          if(isConnected()){
              mTextView.setText("Loading...");
              new HttpAsyncTask().execute("my json url");
          }
          else{
              mTextView.setBackgroundColor(0xffcc0000);
              mTextView.setText("You are NOT connected");
          }
        }
    }

    public boolean isConnected(){
         ConnectivityManager connMgr = (ConnectivityManager) getSystemService(this.CONNECTIVITY_SERVICE);
             NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
             if (networkInfo != null && networkInfo.isConnected()) 
                 return true;
             else
                 return false;   
     }

    public static String GET(String url){
         InputStream inputStream = null;
         String result = "";
         try {

             // create HttpClient
             HttpClient httpclient = new DefaultHttpClient();

             // make GET request to the given URL
             HttpResponse httpResponse = httpclient.execute(new HttpGet(url));

             // receive response as inputStream
             inputStream = httpResponse.getEntity().getContent();

             // convert inputstream to string
             if(inputStream != null)
                 result = convertInputStreamToString(inputStream);
             else
                 result = "Did not work!";

         } catch (Exception e) {
             Log.d("InputStream", e.getLocalizedMessage());
         }

         return result;
     }

    private static String convertInputStreamToString(InputStream inputStream) throws IOException{
         BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
         String line = "";
         String result = "";
         while((line = bufferedReader.readLine()) != null)
             result += line;

         inputStream.close();
         return result;
     }

     private class HttpAsyncTask extends AsyncTask<String, Void, String> {
            @Override
            protected String doInBackground(String... urls) {

                return GET(urls[0]);
            }
            // onPostExecute displays the results of the AsyncTask.
            @Override
            protected void onPostExecute(String result) {
                Toast.makeText(getBaseContext(), "Received!", Toast.LENGTH_LONG).show();

                try {
                    JSONObject jsonobject = new JSONObject(result);
                    mTextView.setText((String) jsonobject.get("count"));

                    Integer count = Integer.parseInt((String) jsonobject.get("count"));

                    if (count == 0) {
                        // There are no results
                        mTextView.setText(getString(R.string.no_results, query));
                    } else {
                        // Display the number of results
                        String countString = getResources().getQuantityString(R.plurals.search_results,
                                count, new Object[] {count, query});
                        mTextView.setText(countString);



                        // Specify the columns we want to display in the result
                        String[] from = new String[] { "title",
                                                       "artist",
                                                       "duration",
                                                       "url"};

                        // Specify the corresponding layout elements where we want the columns to go
                        int[] to = new int[] { R.id.title,
                                               R.id.artist,
                                               R.id.duration,
                                               R.id.url};

                        // -- container for all of our list items
                        List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();

                        // -- list item hash re-used
                        Map<String, String> group;

                        //create audio json array
                        JSONArray audios = jsonobject.getJSONArray("audio");

                        for (int i = 0; i < audios.length(); i++) {
                            JSONObject audio = audios.getJSONObject(i);

                            //get info
                            String title = audio.getString("title");
                            String artist = audio.getString("artist");
                            String duration = audio.getString("duration");
                            String durationformated = getDurationString(Integer.parseInt(duration));
                            String url = audio.getString("url");

                            // -- create record
                            group = new HashMap<String, String>();

                            group.put( "title", title );
                            group.put( "artist",  artist );
                            group.put( "duration",  durationformated );
                            group.put( "url",  url );

                            groupData.add(group);
                        }

                        SimpleAdapter adapter = new SimpleAdapter(mContext , groupData, R.layout.result, 
                                from,
                                 to );

                        setListAdapter( adapter );
                    }
                } 

                catch (JSONException e)           
                 {                
                    // TODO Auto-generated catch block
                    Log.w("myApp", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");   
                    Log.w("myApp", e);    
                    Log.w("myApp", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"); 
                 }
           }
        }

        private String getDurationString(int seconds) {

            int hours = seconds / 3600;
            int minutes = (seconds % 3600) / 60;
            seconds = seconds % 60;

            return twoDigitString(minutes) + ":" + twoDigitString(seconds);
        }

        private String twoDigitString(int number) {

            if (number == 0) {
                return "00";
            }

            if (number / 10 == 0) {
                return "0" + number;
            }

            return String.valueOf(number);
        }
 }

search.xml：

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".Search" >

     <TextView
             android:id="@+id/text"
             android:textColor="?android:textColorPrimary"
             android:background="@android:drawable/title_bar"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content" />

     <ListView
             android:id="@android:id/list"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
             android:layout_below="@id/text"
              />

 </RelativeLayout>

result.xml：

 <?xml version="1.0" encoding="utf-8"?>

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:orientation="vertical"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"
         android:padding="5dp">

      <TextView
         android:id="@+id/url"
         android:layout_width="0dp"
         android:layout_height="0dp"
         android:visibility="gone"/>

     <TextView
         android:id="@+id/title"
         style="@android:style/TextAppearance.Large"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentLeft="true"
         android:layout_toLeftOf="@+id/play"
         android:singleLine="true"
         android:text="title"
         android:textColor="#000000" />

     <TextView
         android:id="@+id/artist"
         style="@android:style/TextAppearance.Small"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentLeft="true"
         android:layout_below="@id/title"
         android:layout_toLeftOf="@+id/play"
         android:singleLine="true"
         android:text="artist"
         android:textColor="#7D7D7D" />

     <TextView
         android:id="@+id/duration"
         style="@android:style/TextAppearance.Small"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignLeft="@+id/artist"
         android:layout_alignParentBottom="true"
         android:layout_below="@id/artist"
         android:layout_toLeftOf="@+id/play"
         android:singleLine="true"
         android:text="03:24"
         android:textColor="#7D7D7D" />

        <ImageButton
            android:id="@+id/play"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_toLeftOf="@+id/download"
            android:src="@drawable/play" />

        <ImageButton
            android:id="@+id/download"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_alignParentRight="true"
            android:src="@drawable/download" />

 </RelativeLayout>

我已經測試了圖像按鈕上的onclick屬性，但沒有成功： URL到我的線程

所以我搜索了setOnItemClickListener，但我成功完成的就是獲取nullpointerexeption。

如果您有解決方案，請告訴我，謝謝。

Answer 1

您將必須使用自定義ListAdapter 。 在getView()方法中，找到要觀看的視圖，並將偵聽器附加到該視圖。

可以在這里找到有關如何實現自定義ListAdapter很好的教程： http : ListAdapter 。 您將要看一下ArrayAdapter的示例實現。 基本上，您必須創建一個對象來表示數據的每一行。 將這些對象的數組傳遞給適配器，適配器將使用getView()方法中的數據填充每個列表項中的視圖。