我有这个代码:
// elementi
setContentView(R.layout.index);
final ListView lista_menu=(ListView) findViewById(R.id.list_menu);
// lista
String[] from=new String[]{"immagine","testo"};
int[] to=new int[]{R.id.immagine_menu,R.id.testo_elemento_menu};
List<HashMap<String,Object>> riempimento=new ArrayList<HashMap<String,Object>>();
HashMap<String,Object> map=new HashMap<String,Object>();
map.put("immagine",R.drawable.icon_converter);
map.put("testo","Convertitore");
riempimento.add(map);
map=new HashMap<String,Object>();
map.put("immagine",R.drawable.icon_noise);
map.put("testo","Noise Analyzer");
riempimento.add(map);
map=new HashMap<String,Object>();
map.put("immagine",R.drawable.icon_tools);
map.put("testo","Tempco Tools");
riempimento.add(map);
map=new HashMap<String,Object>();
map.put("immagine",R.drawable.icon_qrcode);
map.put("testo","Lettore QR Code");
riempimento.add(map);
map=new HashMap<String,Object>();
map.put("immagine",R.drawable.icon_rss);
map.put("testo","RSS Reader");
riempimento.add(map);
SimpleAdapter adapter = new SimpleAdapter(this,riempimento,R.layout.lista,from,to);
lista_menu.setAdapter(adapter);
// intents
lista_menu.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view,int position, long _id){
switch(position){
case 0:
break;
case 1:
break;
case 2:
break;
case 3:
break;
case 4:
Intent intent_rss=new Intent(getParent(),RSS.class);
startActivity(intent_rss);
break;
default:
break;
}
}
});
但是当我点击元素 4 时,应用程序崩溃了......我不知道为什么 :-| 我认为里面没有奇怪的想法......只是一个正常的意图。我需要为每个项目抛出一个意图,我现在正在尝试使用第四个(就位)元素。
logcat(总是不全面):
11-28 17:13:24.731: E/AndroidRuntime(11855): FATAL EXCEPTION: main
11-28 17:13:24.731: E/AndroidRuntime(11855): java.lang.NullPointerException
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.content.ComponentName.<init>(ComponentName.java:75)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.content.Intent.<init>(Intent.java:2702)
11-28 17:13:24.731: E/AndroidRuntime(11855): at it.mi.action.itempco.Index$3.onItemClick(Index.java:80)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.widget.AdapterView.performItemClick(AdapterView.java:284)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.widget.ListView.performItemClick(ListView.java:3513)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.os.Handler.handleCallback(Handler.java:587)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.os.Handler.dispatchMessage(Handler.java:92)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.os.Looper.loop(Looper.java:123)
11-28 17:13:24.731: E/AndroidRuntime(11855): at android.app.ActivityThread.main(ActivityThread.java:3683)
11-28 17:13:24.731: E/AndroidRuntime(11855): at java.lang.reflect.Method.invokeNative(Native Method)
11-28 17:13:24.731: E/AndroidRuntime(11855): at java.lang.reflect.Method.invoke(Method.java:507)
11-28 17:13:24.731: E/AndroidRuntime(11855): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
11-28 17:13:24.731: E/AndroidRuntime(11855): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
11-28 17:13:24.731: E/AndroidRuntime(11855): at dalvik.system.NativeStart.main(Native Method)