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* 我試圖動態地將項目添加到列表視圖。但是,我得到一個運行時異常。請幫助。 全局變量「值」有問題嗎? 我試圖通過打印日誌來調試,我能夠看到存儲在變量*java.lang.RuntimeException:無法啓動活動ComponentInfo:java.lang.NullPointerException:storage == null
public class FriendsActivity extends ListFragment implements TabListener {
private Fragment mFragment;
private String[] values;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActivity().setContentView(R.layout.activity_friends);
}
@SuppressWarnings("deprecation")
public void onActivityCreated(Bundle savedInstanceState) {
setHasOptionsMenu(true);
super.onActivityCreated(savedInstanceState);
String su = User.getLoggedInUsername();
friends.query(friends.class, new StackMobQuery().field(new StackMobQueryField("uname").isEqualTo(su)), new StackMobQueryCallback<friends>(){
@Override
public void failure(StackMobException arg0) {
// TODO Auto-generated method stub
}
public void success(List<friends> arg0) {
// TODO Auto-generated method stub
if(arg0.size()>0){
FriendsActivity.this.values = new String[arg0.size()];
for(int i=0;i<arg0.size();i++){
friends us = arg0.get(i);
values[i] = us.getUname();
}
for(int i=0;i<values.length;i++)
Log.i("Friends",values[i]);
}
else{
values = new String[]{"xyz","abc","dbz"};
}
}
});
//String uname=User.getLoggedInUsername();
//Log.i("User Name",uname);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, values);
setListAdapter(adapter);
}
這裏的值是
05-27 16:42:03.667: E/Trace(814): error opening trace file: No such file or directory (2)
05-27 16:46:17.718: E/AndroidRuntime(814): FATAL EXCEPTION: main
05-27 16:46:17.718: E/AndroidRuntime(814): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myapp.cloudchat/com.myapp.cloudchat.HomeScreenActivity}: java.lang.NullPointerException: storage == null
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.os.Handler.dispatchMessage(Handler.java:99)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.os.Looper.loop(Looper.java:137)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.ActivityThread.main(ActivityThread.java:5041)
05-27 16:46:17.718: E/AndroidRuntime(814): at java.lang.reflect.Method.invokeNative(Native Method)
05-27 16:46:17.718: E/AndroidRuntime(814): at java.lang.reflect.Method.invoke(Method.java:511)
05-27 16:46:17.718: E/AndroidRuntime(814): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-27 16:46:17.718: E/AndroidRuntime(814): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-27 16:46:17.718: E/AndroidRuntime(814): at dalvik.system.NativeStart.main(Native Method)
05-27 16:46:17.718: E/AndroidRuntime(814): Caused by: java.lang.NullPointerException: storage == null
05-27 16:46:17.718: E/AndroidRuntime(814): at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
05-27 16:46:17.718: E/AndroidRuntime(814): at java.util.Arrays.asList(Arrays.java:154)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:128)
05-27 16:46:17.718: E/AndroidRuntime(814): at com.myapp.cloudchat.FriendsActivity.onActivityCreated(FriendsActivity.java:74)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.Fragment.performActivityCreated(Fragment.java:1703)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:903)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1057)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.BackStackRecord.run(BackStackRecord.java:682)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.Activity.performStart(Activity.java:5113)
05-27 16:46:17.718: E/AndroidRuntime(814): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2153)
05-27 16:46:17.718: E/AndroidRuntime(814): ... 11 more
05-27 16:46:20.428: E/Trace(866): error opening trace file: No such file or directory (2)
這應該是接受的答案 – Nactus