我经历了很多问题，虽然这个问题似乎重复，但事实并非如此！
我想将一个活动中的两个字符串传递给一个片段，但我没有这样做会出现以下错误：In [1]: solve(10, 100)
Out[1]: 250639233987229485923025924628548154758061157
In [2]: %timeit solve(10, 100)
1000 loops, best of 3: 964 µs per loop
这是java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference at com.abc.xyz.PostARequest$2$2.run(PostARequest.java:154)（片段）文件的代码：
PostARequest.java这是public class PostARequest extends Fragment {
Bitmap bitmap;
ImageView hPic;
boolean hasDrawable;
EditText hsDescription;
TextView hPicTag, hLocationTag, currentCoordinatesTag, currentLat, currentLng;
LinearLayout latContainer, lngContainer;
Bundle b;
TabHost tabHost;
String latitude, longitude;
private OnFragmentInteractionListener mListener;
public PostARequest() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment PostARequest.
*/
// TODO: Rename and change types and number of parameters
public static PostARequest newInstance(String param1, String param2) {
PostARequest fragment = new PostARequest();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_post_a_request, container, false);
// check for location here
currentCoordinatesTag = (TextView) rootView.findViewById(R.id.currentCoordinatesTag);
latContainer = (LinearLayout) rootView.findViewById(R.id.latContainer);
currentLat = (TextView) rootView.findViewById(R.id.currentLat);
lngContainer = (LinearLayout) rootView.findViewById(R.id.lngContainer);
currentLng = (TextView) rootView.findViewById(R.id.currentLng);
currentCoordinatesTag.setVisibility(View.INVISIBLE);
latContainer.setVisibility(View.INVISIBLE);
currentLat.setVisibility(View.INVISIBLE);
lngContainer.setVisibility(View.INVISIBLE);
currentLng.setVisibility(View.INVISIBLE);
tabHost = new TabHost(getContext());
b = this.getArguments();
hLocationTag = (TextView) rootView.findViewById(R.id.h_location_tag);
hLocationTag.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent mapsIntent = new Intent(getContext(), MapsActivity.class);
startActivity(mapsIntent);
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
homelessLocationTag.setVisibility(View.INVISIBLE);
}
}, 500);
final Handler handler2 = new Handler();
handler2.postDelayed(new Runnable() {
@Override
public void run() {
currentCoordinatesTag.setVisibility(View.VISIBLE);
latContainer.setVisibility(View.VISIBLE);
currentLat.setVisibility(View.VISIBLE);
lngContainer.setVisibility(View.VISIBLE);
currentLng.setVisibility(View.VISIBLE);
latitude = b.getString("latitude");
longitude = b.getString("longitude");
currentLat.setText(latitude);
currentLng.setText(longitude);
tabHost.setCurrentTab(2);
}
}, 15000);
}
});
}
（活动）文件的代码：
MapsActivity.java我真的不知道这里有什么问题。
请告诉我。
如果问题不完整，请合作，我还在学习发表好问题。
答案 0 :(得分：0)
你没有在Fragment中调用newInstance（）。
使用
PostFragment.newInstance(latitude, longitude);
在Fragment中设置那些全局变量：
this.latitude = latitude;
this.longitude = longitude;