public class MainActivity extends AppCompatActivity implements
GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener,
LocationListener {
private GoogleApiClient googleApiClient;
private LocationRequest locationRequest;
private Geocoder geocoder;
private List<Address> addressList;
private TextView showLatTV, showAddrTV;
private String currentLat = null, currentLng = null;
private Bundle bundle;
private String apiTemp, apiArea,apiCountry,weatherCondition,apiSunrise,apiSunset,apiHumidity ;
String weatherUrl = "http://api.openweathermap.org/data/2.5/weather?lat=49&lon=26&APPID=8e401c96e74d2f0c07da113eb27d51d0";
private final String BASE_URL = "http://api.openweathermap.org/";
private WeatherData weatherData;
private WeatherServiceAPI weatherServiceAPI;
// Main Activity OnCreate Method Starts *********
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
showLatTV = (TextView) findViewById(R.id.showLat);
showAddrTV = (TextView) findViewById(R.id.showAddr);
geocoder = new Geocoder(this);
googleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
//Retrofit Starts ************************************
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
weatherServiceAPI = retrofit.create(WeatherServiceAPI.class);
currentLat=String.valueOf(23.810); currentLng= String.valueOf(90.412);
String dynamicUrl = BASE_URL+"data/2.5/weather?lat="+currentLat+"&lon="+currentLng+"&APPID=8e401c96e74d2f0c07da113eb27d51d0";
Call<WeatherData>weatherResponse = weatherServiceAPI.getWeatherResponse(dynamicUrl);
weatherResponse.enqueue(new Callback<WeatherData>() {
@Override
public void onResponse(Call<WeatherData> call, Response<WeatherData> response) {
WeatherData weatherData=response.body();
//Toast.makeText(MainActivity.this, "Got It", Toast.LENGTH_SHORT).show();
apiTemp = weatherData.getMain().getTemp().toString();
apiArea = weatherData.getName().toString();
apiCountry = weatherData.getSys().getCountry().toString();
apiSunrise = weatherData.getSys().getSunrise().toString();
apiSunset = weatherData.getSys().getSunset().toString();
apiHumidity = weatherData.getMain().getHumidity().toString();
weatherCondition = weatherData.getWeather().get(0).getMain().toString();
// areaTV.setText(city);
Toast.makeText(MainActivity.this, " City :"+apiTemp, Toast.LENGTH_SHORT).show();
}
@Override
public void onFailure(Call<WeatherData> call, Throwable t) {
Toast.makeText(MainActivity.this, ""+t.getMessage(), Toast.LENGTH_SHORT).show();
Log.e("weather", "onFailure: "+t.getMessage() );
}
});
//Retrofit Ends ************************************
bundle = new Bundle();
bundle.putString("temperature",apiTemp);
bundle.putString("areaName",apiArea);
bundle.putString("country",apiCountry);
bundle.putString("sunrise",apiSunrise);
bundle.putString("sunset",apiSunset);
bundle.putString("humidity",apiHumidity);
bundle.putString("condition",weatherCondition);
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
FragmentCurrent fragmentCurrent = new FragmentCurrent();
fragmentCurrent.setArguments(bundle);
ft.add(R.id.fragmentContainer, fragmentCurrent);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.addToBackStack(null);
ft.commit();
}
// Main Activity Oncreate Method Ends *****************
//Change Fragment OnClick Method Starts ****************
public void changeWeather(View view) {
Fragment fragment = null;
switch (view.getId()) {
case R.id.fragmentCurrent:
fragment = new FragmentCurrent();
bundle.putString("temperature",apiTemp);
bundle.putString("areaName",apiArea);
bundle.putString("country",apiCountry);
bundle.putString("sunrise",apiSunrise);
bundle.putString("sunset",apiSunset);
bundle.putString("humidity",apiHumidity);
bundle.putString("condition",weatherCondition);
break;
case R.id.fragmentForecast:
fragment = new FragmentForecast();
// bundle.putInt("b",b);
break;
}
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
//fragment.setArguments(bundle);
ft.replace(R.id.fragmentContainer, fragment);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.addToBackStack(null);
ft.commit();
}
//Change Fragment OnClick Method Ends ******************
@Override
protected void onStart() {
super.onStart();
googleApiClient.connect();
}
@Override
protected void onPause() {
googleApiClient.disconnect();
super.onPause();
}
@Override
public void onConnected(@Nullable Bundle bundle) {
locationRequestUpdate();
}
public void locationRequestUpdate(){
locationRequest = locationRequest.create()
.setInterval(1000)
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
return;
}
LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
showLatTV.setText(String.valueOf(location.getLatitude()));
try {
addressList = geocoder.getFromLocation(location.getLatitude(),
location.getLongitude(),1);
String addr = addressList.get(0).getAddressLine(0);
String country = addressList.get(0).getCountryName();
showAddrTV.setText(addr+"\n"+country);
} catch (IOException e) {
e.printStackTrace();
}
}
}
My Fragmet Code：
public class FragmentCurrent extends Fragment {
private TextView tempTV,areaTV,countryTV,sunriseTV,sunsetTV,humidityTV,conditionTV;
public FragmentCurrent() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
String temperature = getArguments().getString("temperature");
String areaName = getArguments().getString("areaName");
String country = getArguments().getString("country");
String sunrise = getArguments().getString("sunrise");
String sunset = getArguments().getString("sunset");
String humidity = getArguments().getString("humidity");
String weatherCondition = getArguments().getString("condition");
tempTV = (TextView) getView().findViewById(R.id.showTemperature);
sunriseTV = (TextView) getView().findViewById(R.id.showSunrise);
sunsetTV = (TextView) getView().findViewById(R.id.showSunset);
conditionTV = (TextView) getView().findViewById(R.id.showCondition);
tempTV.setText(temperature);
sunriseTV.setText(sunrise);
sunsetTV.setText(sunset);
conditionTV.setText(weatherCondition);
View view = inflater.inflate(R.layout.fragment_fragment_currrent, container, false);
return view;
}
}
logcat的：
04-22 00:05:46.234 2684-2684/? E/libprocessgroup: failed to make and chown /acct/uid_10071: Read-only file system
04-22 00:05:48.331 2684-2684/com.example.forever.weather E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.forever.weather, PID: 2684
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.forever.weather/com.example.forever.weather.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
at com.example.forever.weather.FragmentCurrent.onCreateView**(FragmentCurrent.java:37)**
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2192)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1299)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1528)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1595)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:758)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2363)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2149)
at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2103)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2013)
at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:388)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:607)
at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:178)
at com.example.forever.weather.MainActivity.onStart**(MainActivity.java:161)**
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1236)
at android.app.Activity.performStart(Activity.java:6006)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2288)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
我无法在Fragment中传递数据。它给出了NullPointerException，这意味着数据不会进入Fragment。请有人帮助我如何在Fragment中传递Retrofit API数据，或者有人能告诉我如何以简单的方式传递Fragment中的改造数据？
答案 0 :(得分：1)
在您有意见之前，您正在致电getView()！
试试这个
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_fragment_currrent, container, false);
tempTV = (TextView) view.findViewById(R.id.showTemperature);
// find others without using getView()
// then get arguments
// then set the view data
return view;
}
您还希望在public void onResponse(内制作和添加片段，否则，您的数据将作为未分配和null传递（因为您的请求尚未完成）
答案 1 :(得分：0)
你的问题在于你在片段中使用视图的方式，在onCreateView的末尾你实例化一个视图对象，而不是使用getView，使用视图对象本身来查找布局中的视图
View view = inflater.inflate(R.layout.fragment_fragment_currrent, container, false);
该声明应该是第一个，然后例如做
tempTV = (TextView) view.findViewById(R.id.showTemperature);
sunriseTV = (TextView) view.findViewById(R.id.showSunrise);
sunsetTV = (TextView) view.findViewById(R.id.showSunset);
conditionTV = (TextView)view.findViewById(R.id.showCondition);