问题
I like to pass selected item value from ListView to another activity.
I am using this code to get the details associated with the hashmap but I get 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();
}
How do I fix it.I really appreciate the help.
Thanks in Advance.
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();
}
});
}
}
BUT the same code BELOW works : WHY ?
It is a SimpleAdapter in this case.
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();
}
});
}
}
回答1:
try to replace
HashMap<String, String> o = (HashMap<String, String>) list.getItemAtPosition(position);
with
int o = (int) list.getItemAtPosition(position);
it seems your listview items contains the int
type values
来源:https://stackoverflow.com/questions/15799663/listview-lazyadapter