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我喜欢将所选项目值从 ListView 传递到另一个活动。

我正在使用此代码来获取与哈希图关联的详细信息，但我得到java.lang.Integer cannot be cast to java.util.HashMap。 

public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {


                HashMap<String, String> o = (HashMap<String, String>) list.getItemAtPosition(position);
                Toast.makeText(CustomizedListView.this, "ID '" + o.get("KEY_TITLE") + "' was clicked.", Toast.LENGTH_SHORT).show(); 

            }

我该如何解决它。我非常感谢您的帮助。

提前致谢。

public class CustomizedListView extends Activity {
    // All static variables
    static final String URL = "https://itunes.apple.com/us/rss/topalbums/limit=20/json";
    // XML node keys
    static final String KEY_SONG = "song"; // parent node
    static final String KEY_ID = "id";
    static final String KEY_TITLE = "title";
    static final String KEY_ARTIST = "artist";
    static final String KEY_DURATION = "duration";
    static final String KEY_THUMB_URL = "thumb_url";

    ListView list;
    LazyAdapter adapter;

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


        ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();

        JSONObject json = JSONfunctions.getJSONfromURL(URL);


        try {
            JSONObject arr2 = json.getJSONObject("feed");
            JSONArray arr = arr2.getJSONArray("entry");

            for (int i = 0; i < arr.length(); i++) {
                JSONObject e1 = arr.getJSONObject(i);

                JSONArray arr3 = e1.getJSONArray("im:image");

                JSONObject arr8 = e1.getJSONObject("im:name");

                JSONObject arr10 = e1.getJSONObject("im:artist");

                    JSONObject e12 = arr3.getJSONObject(0);

            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            map.put(KEY_THUMB_URL,  e12.getString("label"));

            map.put(KEY_ARTIST, arr8.getString("label"));
            map.put(KEY_TITLE, arr10.getString("label"));
            // adding HashList to ArrayList
            songsList.add(map);
            }

        } catch (JSONException e) {
            // Log.e("log_tag", "Error parsing data "+e.toString());
            Toast.makeText(getBaseContext(),
                    "Network communication error!", 5).show();
        }


        list=(ListView)findViewById(R.id.list);

        // Getting adapter by passing xml data ArrayList
        adapter=new LazyAdapter(this, songsList);        
        list.setAdapter(adapter);

        // Click event for single list row
        list.setOnItemClickListener(new OnItemClickListener() {

            @SuppressWarnings("unchecked")
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {


                HashMap<String, String> o = (HashMap<String, String>) list.getItemAtPosition(position);
                Toast.makeText(CustomizedListView.this, "ID '" + o.get("KEY_TITLE") + "' was clicked.", Toast.LENGTH_SHORT).show(); 

            }
        });     
    }   
}

但下面的相同代码有效：为什么？

在这种情况下，它是一个SimpleAdapter 。

public class Main extends ListActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listplaceholder);

        ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();


        JSONObject json = JSONfunctions.getJSONfromURL("http://api.geonames.org/earthquakesJSON?north=44.1&south=-9.9&east=-22.4&west=55.2&username=demo");

        try{

            JSONArray  earthquakes = json.getJSONArray("earthquakes");

            for(int i=0;i<earthquakes.length();i++){                        
                HashMap<String, String> map = new HashMap<String, String>();    
                JSONObject e = earthquakes.getJSONObject(i);

                map.put("id",  String.valueOf(i));
                map.put("name", "Earthquake name:" + e.getString("eqid"));
                map.put("magnitude", "Magnitude: " +  e.getString("magnitude"));
                mylist.add(map);            
            }       
        }catch(JSONException e)        {
             Log.e("log_tag", "Error parsing data "+e.toString());
        }

        ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.main, 
                        new String[] { "name", "magnitude" }, 
                        new int[] { R.id.item_title, R.id.item_subtitle });

        setListAdapter(adapter);

        final ListView lv = getListView();
        lv.setTextFilterEnabled(true);  
        lv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {              
                @SuppressWarnings("unchecked")
                HashMap<String, String> o = (HashMap<String, String>) lv.getItemAtPosition(position);                   
                Toast.makeText(Main.this, "ID '" + o.get("id") + "' was clicked.", Toast.LENGTH_SHORT).show(); 

            }
        });
    }
}
4

1 回答 1

1

尝试更换

 HashMap<String, String> o = (HashMap<String, String>) list.getItemAtPosition(position);

和

int o = (int) list.getItemAtPosition(position);

似乎您的列表视图项目包含int类型值

于 2013-04-04T04:48:27.737 回答