我试图通过GoogleApiClient获取坐标。如果我运行应用程序，我会收到以下错误：
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.example.android.pws.fragment.HomeFragment.onCreateView(HomeFragment.java:141)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2080)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1108)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1290)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:801)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1677)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:536)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7230)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
我不知道解决这个问题。我已经在互联网上搜索但没有任何作用。有人可以帮助我吗？
代码：
public class HomeFragment extends Fragment implements GoogleApiClient.OnConnectionFailedListener,
GoogleApiClient.ConnectionCallbacks, com.google.android.gms.location.LocationListener {
private static final String TAG = HomeFragment.class.getSimpleName();
private static final int REQUEST_CODE_PERMISSION = 2;
String mPermission = Manifest.permission.ACCESS_FINE_LOCATION;
private LocationListener listener;
TextView textView;
TextView textView3;
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private static final int MY_PERMISSIONS_REQUEST_SEND_SMS =0;
private static final int REQUEST_CODE_SOME_FEATURES_PERMISSIONS=0;
Location mLastLocation;
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
String lat, lon;
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public HomeFragment() {
}
public static HomeFragment newInstance(String param1, String param2) {
HomeFragment fragment = new HomeFragment();
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) {
View view = inflater.inflate(R.layout.fragment_home,
container, false);
try {
if (ActivityCompat.checkSelfPermission(getActivity(), mPermission)
!= MockPackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(getActivity(), new String[]{mPermission},
REQUEST_CODE_PERMISSION);
// If any permission above not allowed by user, this condition will
//execute every time, else your else part will work
}
} catch (Exception e) {
e.printStackTrace();
}
buildGoogleApiClient();
TextView textView = (TextView) view.findViewById(R.id.textView);
TextView textView3 = (TextView) view.findViewById(R.id.textView3);
textView.setText(lat);
textView3.setText(lon);
int hasLocationPermission = ActivityCompat.checkSelfPermission(getActivity(), android.Manifest.permission.ACCESS_FINE_LOCATION );
int hasSMSPermission = ActivityCompat.checkSelfPermission(getActivity(), android.Manifest.permission.SEND_SMS );
int hasCoarseLocation = ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_COARSE_LOCATION);
List<String> permissions = new ArrayList<String>();
if( hasLocationPermission != PackageManager.PERMISSION_GRANTED ) {
permissions.add( android.Manifest.permission.ACCESS_FINE_LOCATION );
}
if( hasSMSPermission != PackageManager.PERMISSION_GRANTED ) {
permissions.add( android.Manifest.permission.SEND_SMS );
}
if (hasCoarseLocation != PackageManager.PERMISSION_GRANTED) {
permissions.add(Manifest.permission.ACCESS_COARSE_LOCATION);
}
if( !permissions.isEmpty() ) {
requestPermissions( permissions.toArray( new String[permissions.size()] ), REQUEST_CODE_SOME_FEATURES_PERMISSIONS );
}
Button button = (Button) view.findViewById(R.id.push_button);
SharedPreferences pref = getActivity().getApplicationContext().getSharedPreferences(Config.SHARED_PREF, 0);
final String telNumber = pref.getString("number", null);
final String message = "";
button.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
if (!TextUtils.isEmpty(telNumber)) {
SmsManager smsManager = SmsManager.getDefault();
smsManager.sendTextMessage(telNumber, null, message, null, null);
Toast.makeText(getActivity().getApplicationContext(), "SMS sent.",
Toast.LENGTH_LONG).show();
openDialer();
}
else {
Toast.makeText(getActivity().getApplicationContext(), "Er is geen emergency contact toegevoegd.",
Toast.LENGTH_LONG).show();
}
}
});
return view;
}
private void openDialer() {
Intent intent = new Intent(Intent.ACTION_DIAL);
intent.setData(Uri.parse("tel:0123456789"));
startActivity(intent);
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch ( requestCode ) {
case REQUEST_CODE_SOME_FEATURES_PERMISSIONS: {
for( int i = 0; i < permissions.length; i++ ) {
if( grantResults[i] == PackageManager.PERMISSION_GRANTED ) {
Log.d( "Permissions", "Permission Granted: " + permissions[i] );
} else if( grantResults[i] == PackageManager.PERMISSION_DENIED ) {
Log.d( "Permissions", "Permission Denied: " + permissions[i] );
}
}
}
break;
default: {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
}
@Override
public void onConnected(Bundle bundle) {
mLocationRequest = LocationRequest.create();
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationRequest.setInterval(100); // Update location every second
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
if (ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION,Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.INTERNET}
,10);
}
return;
}
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
mGoogleApiClient);
if (mLastLocation != null) {
lat = String.valueOf(mLastLocation.getLatitude());
lon = String.valueOf(mLastLocation.getLongitude());
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onLocationChanged(Location location) {
lat = String.valueOf(location.getLatitude());
lon = String.valueOf(location.getLongitude());
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
buildGoogleApiClient();
}
synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
@Override
public void onStart() {
super.onStart();
mGoogleApiClient.connect();
}
@Override
public void onDestroy() {
super.onDestroy();
mGoogleApiClient.disconnect();
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
答案 0 :(得分：0)
崩溃是因为您尝试将文本设置为具有空指针引用的文本视图。检查布局fragment_home.xml是否具有带有textview和textview3的TextView。崩溃发生在HomeFragment的第141行。
答案 1 :(得分：0)
您的一个观看次数textView或textView3未在Home Fragment.xml中分配了ID