public class PendingMessageFragment extends Fragment {
RegistrationAdapter adapter_ob;
RegistrationAdapter adapter_time;
RegistrationOpenHelper helper_ob;
ArrayList<MessageModel> pendingdata;
ListView pendinglist;
int j;
SQLiteDatabase db_ob;
ListView nameList;
Button registerBtn;
Cursor c;
Cursor cursor;
Bitmap bitmap;
TextView ptimeview;
ImageView postedimageviewrow;
StringBuffer now3;
String cool;
Time present;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View V = inflater.inflate(R.layout.pendingmessage, container, false);
pendinglist=(ListView) V.findViewById(R.id.lv_name);
pendingdata=new ArrayList<MessageModel>();
adapter_ob = new RegistrationAdapter(getActivity());
adapter_time=new RegistrationAdapter(getActivity());
cursor=adapter_ob.queryName();
Log.d("value of cursor in pendfrag is",""+cursor);
cursor.moveToFirst();
for(int i=0;i<cursor.getCount();i++)
{
MessageModel m=new MessageModel();
m.setKey_Id(cursor.getString(cursor.getColumnIndex("_id")));
m.setF_NAME(cursor.getString(cursor.getColumnIndex("F_NAME")));
m.setF_Time(cursor.getString(cursor.getColumnIndex("F_Time")));
pendingdata.add(m);
cursor.moveToNext();
}
c=adapter_time.queryTime();
Log.d("value of c befor onclick",""+c);
pendinglist.setAdapter(new MyPendingAdapter(getActivity(),pendingdata));
pendinglist.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Bundle passdata = new Bundle();
Log.d("arg0 is",""+arg0);
Log.d("arg2 is",""+arg2);
//Here Getting arg0 and arg2 but in next line geeting null in listcursor.
Cursor listCursor = (Cursor) arg0.getItemAtPosition(arg2);
Log.d("listcursor is",""+listCursor);
Log.d("column index is",""+j);
int nameId = listCursor.getInt(listCursor
.getColumnIndex(helper_ob.KEY_ID));
c=adapter_time.queryAll2(nameId);
Intent passIntent = new Intent(getActivity(),
EditActivity.class);
passIntent.putExtras(passdata);
startActivity(passIntent);
}
catch(ParseException e)
{
e.printStackTrace();
}
}
});
return V;
}
class MyPendingAdapter extends BaseAdapter
{
Activity activity;
ArrayList<MessageModel> arraylist;
public MyPendingAdapter(Activity a,ArrayList<MessageModel> arr) {
// TODO Auto-generated constructor stub
this.activity=a;
this.arraylist=arr;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
j=arraylist.size();
return arraylist.size();
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int arg0, View arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
View v=getActivity().getLayoutInflater().inflate(R.layout.row,null);
arg0=j-arg0-1;
TextView t1=(TextView) v.findViewById(R.id.tv_fname);
TextView t2=(TextView) v.findViewById(R.id.ptime);
ImageView v1=(ImageView) v.findViewById(R.id.pendingimageviewrow);
bitmap=BitmapFactory.decodeResource(getActivity().getResources(),R.drawable.receviedpostedlogo);
v1.setImageBitmap(bitmap);
Log.d("pending message fragment time is",""+arraylist.get(arg0).getF_Time());
t1.setText(arraylist.get(arg0).getF_NAME());
t2.setText(arraylist.get(arg0).getF_Time());
Log.d("the time is",""+arraylist.get(arg0).getF_Time());
Log.d("t2 text is",""+t2.getText().toString());
return v;
}
}
@Override
public void onResume() {
super.onResume();
cursor.requery();
}
}
本程序正在从数据库中选择正确保存的数据，我在listview上显示数据，但是当点击任何项目时，它会在获取onclickitem数据时显示空指针异常。
日志
11-25 11:42:48.779: D/arg0 is(1456): android.widget.ListView@40f646b0
11-25 11:42:48.779: D/arg2 is(1456): 2
11-25 11:42:48.779: D/listcursor is(1456): null
11-25 11:42:48.789: D/column index is(1456): 3
11-25 11:42:48.789: D/AndroidRuntime(1456): Shutting down VM
11-25 11:42:48.789: W/dalvikvm(1456): threadid=1: thread exiting with uncaught exception (group=0x40c1fa68)
11-25 11:42:48.799: E/AndroidRuntime(1456): FATAL EXCEPTION: main
11-25 11:42:48.799: E/AndroidRuntime(1456): java.lang.NullPointerException
11-25 11:42:48.799: E/AndroidRuntime(1456): at com.example.gate_keeper.PendingMessageFragment$1.onItemClick(PendingMessageFragment.java:98)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.widget.AdapterView.performItemClick(AdapterView.java:292)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.widget.AbsListView.performItemClick(AbsListView.java:1394)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.widget.AbsListView$PerformClick.run(AbsListView.java:3024)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.widget.AbsListView$1.run(AbsListView.java:3830)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.os.Handler.handleCallback(Handler.java:605)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.os.Handler.dispatchMessage(Handler.java:92)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.os.Looper.loop(Looper.java:137)
11-25 11:42:48.799: E/AndroidRuntime(1456): at android.app.ActivityThread.main(ActivityThread.java:4517)
11-25 11:42:48.799: E/AndroidRuntime(1456): at java.lang.reflect.Method.invokeNative(Native Method)
11-25 11:42:48.799: E/AndroidRuntime(1456): at java.lang.reflect.Method.invoke(Method.java:511)
11-25 11:42:48.799: E/AndroidRuntime(1456): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
11-25 11:42:48.799: E/AndroidRuntime(1456): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
11-25 11:42:48.799: E/AndroidRuntime(1456): at dalvik.system.NativeStart.main(Native Method)
11-25 11:42:48.829: E/AlarmManagerService(378): android_server_AlarmManagerService_set to type=3, 116.173000000
答案 0 :(得分：0)
尝试从列表数据持有者中获取选定的列表项数据：
int nameId = pendingdata.get(arg2).getKey_Id();
而不是：
int nameId = listCursor.getInt(listCursor.getColumnIndex(helper_ob.KEY_ID));
答案 1 :(得分：0)
使用
解决了问题int nameId = pendingdata.get（arg2）.getKey_Id（）;
而不是：
int nameId = listCursor.getInt（listCursor.getColumnIndex（helper_ob.KEY_ID））;