Onclicklistener返回從活動不工作的片段

Question

我想從活動返回到我的主要片段，當我單擊列表視圖中的項目時，我也希望它將一些文本傳回給視圖。不幸的是，我還沒有成功地做到這一點，我在下面發佈的代碼給出了「返回fragobj」的錯誤。說它：

不能從一個方法爲void結果類型返回一個值

ActivityView：

package com.example.curtisboylan.myapplication; 

import android.content.Intent; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ListView; 
import android.widget.Toast; 

import java.util.ArrayList; 

public class DevicesList extends AppCompatActivity { 

    private DeviceListAdapter dlAdapter; 
    private ArrayList<String> listType; 
    private ArrayList<Integer> listIcon; 
    private ListView gridView; 
    private String type; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_devices_list); 

     Bundle bundle = getIntent().getExtras(); 

     String message = bundle.getString("devicetype"); 
     type = message; 
     // Toast.makeText(this, "DEBUGTYPE: " + message, Toast.LENGTH_SHORT).show(); 

     setTitle("Choose Your Device"); 



     prepareList(); 
     // prepared arraylist and passed it to the Adapter class 
     dlAdapter = new DeviceListAdapter(DevicesList.this, listType, listIcon); 


     // Set custom adapter to gridview 
     gridView = (ListView) this.findViewById(R.id.GridViewDeviceList); 
     gridView.setAdapter(dlAdapter); 
     dlAdapter.notifyDataSetChanged(); 

     gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int position, 
            long arg3) { 

       Bundle bundle = new Bundle(); 
       bundle.putString("device", dlAdapter.getItem(position)); 
       SearchScreen fragobj = new SearchScreen(); 
       fragobj.setArguments(bundle); 
       return fragobj; 

      } 
     }); 
    } 

    public void prepareList() { 
     listType = new ArrayList<String>(); 

if(type.equals("iphone")) { 
    listType.add("iPhone 7"); 
    listType.add("iPhone 6S"); 
    listType.add("iPhone 6"); 
    listType.add("iPhone 5S"); 
    listType.add("iPhone 5"); 
    listType.add("iPad Pro"); 
    listType.add("iPad"); 
    listType.add("iPad Mini"); 
    listType.add("Other"); 

    setTitle("iPhone Devices"); 
} 

else if(type.equals("android")){ 
    listType.add("Samsung S7"); 
    listType.add("Samsung S6"); 
    listType.add("Samsung S5"); 
    listType.add("Samsung Galaxy Mini"); 
    listType.add("Nexus Pro"); 
    listType.add("HTC One"); 
    listType.add("Google Pixel"); 
    listType.add("Other"); 

    setTitle("Android Devices"); 
} 

    else if(type.equals("windows")) { 
      listType.add("windows 10"); 
      listType.add("windows 8"); 
      listType.add("windows 7"); 
      listType.add("Other"); 

     setTitle("Windows PC"); 

     } 

    else if(type.equals("mac")) { 
      listType.add("iMac Pro"); 
      listType.add("iMac"); 
      listType.add("Other"); 

    setTitle("Apple Mac PC"); 

     } 

    else if(type.equals ("console")) { 
      listType.add("Xbox One"); 
      listType.add("Xbox 360"); 
      listType.add("PS4"); 
      listType.add("PS4 Pro"); 
      listType.add("Nintendo Switch"); 
      listType.add("Nintendo Wii U"); 
      listType.add("Other"); 

    setTitle("Consoles"); 

     } 

    else if(type.equals ("laptop")) { 
      listType.add("windows 10"); 
      listType.add("windows 8"); 
      listType.add("windows 7"); 
      listType.add("Other"); 

    setTitle("Laptops"); 

     } 

    else if(type.equals ("camera")) { 
      listType.add("Nikon"); 
      listType.add("FujiFilm"); 
      listType.add("Sony"); 
      listType.add("Olympus"); 
      listType.add("Kodak"); 
      listType.add("Leica"); 
      listType.add("Pentax"); 
      listType.add("Ricah"); 
      listType.add("Other"); 

    setTitle("Camera"); 

     } 

    else if(type.equals ("printer")) { 
      listType.add("Cannon"); 
      listType.add("Hewlett Packard"); 
      listType.add("Xerox"); 
      listType.add("Epson"); 
      listType.add("Toshiba"); 
      listType.add("Dell"); 
      listType.add("Other"); 

    setTitle("Printers"); 

     } 
     listIcon = new ArrayList<Integer>(); 

    } 
} 

的MainView：

package com.example.curtisboylan.myapplication; 

import android.Manifest; 
import android.app.Activity; 
import android.app.DatePickerDialog; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.pm.PackageManager; 
import android.location.Geocoder; 
import android.location.Location; 
import android.location.LocationManager; 
import android.provider.Settings; 
import android.support.annotation.NonNull; 
import android.support.annotation.Nullable; 
import android.support.v4.app.ActivityCompat; 
import android.support.v4.app.Fragment; 
import android.support.v7.app.AlertDialog; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.GridView; 
import android.widget.TextView; 
import android.content.Intent; 
import android.widget.Button; 
import android.widget.DatePicker; 
import android.widget.Toast; 

import java.io.IOException; 
import java.text.DateFormat; 
import java.util.Calendar; 

import java.util.ArrayList; 
import java.util.List; 
import java.util.Locale; 

import com.google.android.gms.common.ConnectionResult; 
import com.google.android.gms.common.GooglePlayServicesNotAvailableException; 
import com.google.android.gms.common.GooglePlayServicesRepairableException; 
import com.google.android.gms.common.api.GoogleApiClient; 
import com.google.android.gms.location.LocationRequest; 
import com.google.android.gms.location.LocationServices; 
import com.google.android.gms.location.places.Place; 
import com.google.android.gms.location.places.ui.PlaceAutocomplete; 
import com.google.android.gms.maps.model.LatLng; 

import static android.app.Activity.RESULT_CANCELED; 
import static android.app.Activity.RESULT_OK; 
import static com.google.android.gms.wearable.DataMap.TAG; 

public class SearchScreen extends Fragment implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener { 
    public final static String EXTRA_MESSAGE = "com.example.curtisboylan.myapplication"; 

    private GoogleApiClient client; 
    private GridViewAdapter mAdapter; 
    private ArrayList<String> listType; 
    private ArrayList<Integer> listIcon; 
    private String repairtype; 
    private GridView gridView; 

    private TextView tv; 

    private Button contBtn; 
    private Button googleLocBtn; 
    private Button devicepicker; 
    private Button gpsBtn; 
    private boolean setGPSloc = false; 

    private Location mLocation; 
    private LocationManager locationManager; 
    private long UPDATE_INTERVAL = 2 * 1000; /* 10 secs */ 
    private long FASTEST_INTERVAL = 2000; 
    private LocationRequest mLocationRequest; 
    private com.google.android.gms.location.LocationListener listener; 

    private TextView mLatitudeTextView; 
    private TextView mLongitudeTextView; 
    private TextView tv2; 

    Double longitude; 
    Double latitude; 

    public static SearchScreen newInstance(){ 
     SearchScreen fragment = new SearchScreen(); 
     return fragment; 
    } 

    public SearchScreen(){} 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 


     client = new GoogleApiClient.Builder(this.getActivity()) 
       .addConnectionCallbacks(this) 
       .addOnConnectionFailedListener(this) 
       .addApi(LocationServices.API) 
       .build(); 

     locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE); 
     checkLocation(); 

     Intent intent = getActivity().getIntent(); 
     if (intent != null) { 
      //String device = intent.getStringExtra("device"); 
      //String device = bundle.getString("device"); 
      Toast.makeText(getActivity(), "NODEVICE", Toast.LENGTH_SHORT).show(); 
     } else 

     { 
      Toast.makeText(getActivity(), "DEVICESELECTED: " + intent.getStringExtra("device"), Toast.LENGTH_SHORT).show(); 

     } 
    } 





    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 

     final View view = inflater.inflate(R.layout.activity_main, container, false); 

     tv = (TextView) view.findViewById(R.id.textView); 




     prepareList(); 
     repairtype =""; 

     text = (TextView) view.findViewById(R.id.txt_TextDateTime); 
     btn_date = (Button) view.findViewById(R.id.btn_datePicker); 

     btn_date.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       updateDate(); 
      } 
     }); 

     contBtn = (Button) view.findViewById(R.id.button); 
     contBtn.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       //Toast.makeText(getActivity(), "Latitude: " + latitude + "Longitude: " + longitude, Toast.LENGTH_SHORT).show(); 
       Intent intent = new Intent(getActivity(), TechnicianListView.class); 
       intent.putExtra("type", repairtype); 
       intent.putExtra("latitude", latitude); 
       intent.putExtra("longitude", longitude); 
       startActivity(intent); 
      } 
     }); 

     gpsBtn = (Button) view.findViewById(R.id.button3); 
     gpsBtn.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 

        tv2.setText("" + getMyPosAddress(mLocation.getLatitude(), mLocation.getLongitude())); 
       latitude = mLocation.getLatitude(); 
       longitude = mLocation.getLongitude(); 

      } 
     }); 


     tv2 = (TextView) view.findViewById((R.id.textView)); 


     updateTextLabel(); 


     // prepared arraylist and passed it to the Adapter class 
     mAdapter = new GridViewAdapter(getActivity(), listType, listIcon); 

     // Set custom adapter to gridview 
     gridView = (GridView) view.findViewById(R.id.gridView1); 
     gridView.setAdapter(mAdapter); 

     // Implement On Item click listener 
     gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int position, 
            long arg3) { 
       Toast.makeText(getActivity(), "DEBUG " + mAdapter.getItem(position), Toast.LENGTH_SHORT).show(); 
       repairtype = mAdapter.getItem(position); 
      } 
     }); 

     googleLocBtn = (Button) view.findViewById(R.id.googleLocBtn); 
     googleLocBtn.setOnClickListener(new View.OnClickListener() { 
      public void onClick(View v) { 
       findPlace(v.findViewById(android.R.id.content)); 
      } 
     }); 

     devicepicker = (Button) view.findViewById(R.id.devicepick); 
     devicepicker.setOnClickListener(new View.OnClickListener() { 
      public void onClick(View v) { 

       Intent intent = new Intent(getActivity(), DevicePicker.class); 
       // intent.putExtra("message", "test"); 
       startActivity(intent); 

       // devicepicker.setText(getId("devicetype")); 
      } 
     }); 


     return view; 
    } 



    //Calling method DateFormat and Calendar 
    DateFormat formatDateTime = DateFormat.getDateInstance(); 
    Calendar dateTime = Calendar.getInstance(); 
    //Creating Vars 
    private TextView text; 
    private Button btn_date; 


    private void updateDate() { 
     new DatePickerDialog(getActivity(), d, dateTime.get(Calendar.YEAR), dateTime.get(Calendar.MONTH), dateTime.get(Calendar.DAY_OF_MONTH)).show(); 
    } 


    DatePickerDialog.OnDateSetListener d = new DatePickerDialog.OnDateSetListener() { 
     @Override 
     public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) { 
      dateTime.set(Calendar.YEAR, year); 
      dateTime.set(Calendar.MONTH, monthOfYear); 
      dateTime.set(Calendar.DAY_OF_MONTH, dayOfMonth); 
      updateTextLabel(); 
     } 
    }; 


    private void updateTextLabel() { 
     text.setText(formatDateTime.format(dateTime.getTime())); 
    } 


    public void prepareList() { 
     listType = new ArrayList<String>(); 

     listType.add("di1"); 
     listType.add("iphonescreen"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 
     listType.add("placeholder"); 

     listIcon = new ArrayList<Integer>(); 

     listIcon.add(R.drawable.camerabrokenicon); 
     listIcon.add(R.drawable.screenrepairicon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
     listIcon.add(R.drawable.placeholdericon); 
    } 

    public void testBtn(View v) { 
     // tv.setText("Welcome"); 

    } 

    public void findPlace(View v) { 
     try { 
      Intent intent = 
        new PlaceAutocomplete 
          .IntentBuilder(PlaceAutocomplete.MODE_FULLSCREEN) 
          .build(getActivity()); 
      startActivityForResult(intent, 1); 
     } catch (GooglePlayServicesRepairableException e) { 
      // TODO: Handle the error. 
     } catch (GooglePlayServicesNotAvailableException e) { 
      // TODO: Handle the error. 
     } 
    } 

    @Override 
    public void onActivityResult(int requestCode, int resultCode, Intent data) { 
     if (requestCode == 1) { 
      if (resultCode == RESULT_OK) { 
       Place place = PlaceAutocomplete.getPlace(this.getContext(), data); 
       Log.e("Tag", "Place: " + place.getAddress() + place.getPhoneNumber()); 

       ((TextView) getView().findViewById(R.id.textView)) 
         .setText("" + place.getName()); 

       latitude = place.getLatLng().latitude; 
       longitude = place.getLatLng().longitude; 
       Log.e("Tag", "Latitude: " + latitude + "longitude: " + longitude); 


      } else if (resultCode == PlaceAutocomplete.RESULT_ERROR) { 

      } else if (resultCode == RESULT_CANCELED) { 
      } 
     } 
    } 


    @Override 
    public void onStart() { 
     super.onStart(); 
     super.onStart(); 
     if (client != null) { 
      client.connect(); 
     } 


    } 

    @Override 
    public void onStop() { 
     super.onStop(); 
     client.disconnect(); 
    } 


    private String getMyPosAddress(double dbLat, double dbLon) { 
     String addressString = "No address found"; 
     Geocoder gc = new Geocoder(getContext(), Locale.getDefault()); 

     try { 
      List<android.location.Address> gclist ; 

      gclist = gc.getFromLocation(dbLat, dbLon, 1); 


      if (gclist.size() > 0) { 
       android.location.Address address = gclist.get(0); 

       addressString = "" + address.getAddressLine(0) + ", " + address.getAdminArea(); 
      } 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 



     return addressString; 
    } 

    @Override 
    public void onConnected(@Nullable Bundle bundle) { 

     if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
      showAlert(); 
      return; 
     } 
     startLocationUpdates(); 
     mLocation = LocationServices.FusedLocationApi.getLastLocation(client); 
     if(mLocation == null){ 
      startLocationUpdates(); 
     } 
     if (mLocation != null) { 
      latitude = mLocation.getLatitude(); 
      longitude = mLocation.getLongitude(); 
     } 
     else { 

     } 


    } 

    protected void startLocationUpdates() { 
     // Create the location request 
     mLocationRequest = LocationRequest.create() 
       .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY) 
       .setInterval(UPDATE_INTERVAL) 
       .setFastestInterval(FASTEST_INTERVAL); 
     // Request location updates 
     if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
      Log.i("LOCCCC", "loc failed"); 
      startLocationUpdates(); 
     } 
     else{ 
      Log.i("LOCCCC", "loc ok"); 
     } 
     LocationServices.FusedLocationApi.requestLocationUpdates(client, 
       mLocationRequest, this); 
     Log.d("reque", "--->>>>"); 
    } 

    @Override 
    public void onConnectionSuspended(int i) { 
     Log.i(TAG, "Connection Suspended"); 
     client.connect(); 
    } 

    @Override 
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { 
     Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode()); 
    } 

    @Override 
    public void onLocationChanged(Location location) { 

     if(location!= null){ 
      latitude = location.getLatitude(); 
      longitude = location.getLongitude(); 
     } 
     else { 
      String msg = "Updated Location: " + 
        Double.toString(location.getLatitude()) + "," + 
        Double.toString(location.getLongitude()); 

      latitude = mLocation.getLatitude(); 
      longitude = mLocation.getLongitude(); 
      LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
     } 
    } 

    private boolean checkLocation() { 
     if(!isLocationEnabled()) 
      showAlert(); 
     return isLocationEnabled(); 
    } 

    private void showAlert() { 
     final AlertDialog.Builder dialog = new AlertDialog.Builder(getContext()); 
     dialog.setTitle("Enable Location") 
       .setMessage("Your Locations Settings is set to 'Off'.\nPlease Enable Location to " + 
         "use MyGeek") 
       .setPositiveButton("Location Settings", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface paramDialogInterface, int paramInt) { 

         Intent myIntent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
         startActivity(myIntent); 
        } 
       }) 
       .setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface paramDialogInterface, int paramInt) { 

        } 
       }); 
     dialog.show(); 
    } 

    private boolean isLocationEnabled() { 
     locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE); 
     return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) || 
       locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER); 
    } 



} 

Answer 1

的問題是您的OnItemClickListener。 onClick()返回void但您試圖返回片段。下面是引用片段更標準的方式：

在你的活動：

gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
    @Override 
    public void onItemClick(AdapterView<?> arg0, View arg1, int position, 
          long arg3) { 
     SearchScreen fragobj = SearchScreen.newInstance(dlAdapter.getItem(position)); 
     // ...additional processing 
    } 
}); 

在您的片段：

public SearchScreen() { 
    // Null constructor as required by Android 
} 

public static SearchScreen newInstance(String device){ 
    Bundle bundle = new Bundle(); 

    SearchScreen fragment = new SearchScreen(); 
    bundle.putString("device", device); 
    fragment.setArguments(bundle); 
    return fragment; 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    Bundle bundle; 
    String device; 

    super.onCreate(savedInstanceState); 
    bundle = getArguments(); 
    device = bundle.getString("device"); 
    // ...and so on... 
} 

您還可以看看Best practice for instantiating a new Android Fragment和Using newInstance() to Instantiate a Fragment欲瞭解更多信息。