スマートフォンに自分のアプリをインストールすると私のアプリがクラッシュする

Question

私はGPS /ネットワークプロバイダを使用して車の速度を決定するアプリケーションを作成しました。

これは私が試したものですが、コードは問題ありませんが、エラーは発生しませんが、アプリケーションを実行するとクラッシュします。

AndroidGPSTrackingActivity：

package com.example.muhammadshahid.smartsm; 

import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.view.View; 
import android.widget.Button; 
import android.widget.Toast; 

public class AndroidGPSTrackingActivity extends AppCompatActivity { 

    Button btnShowLocation; 
    // GPSTracker class 
    GPSTracker gps; 

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



     // show location button click event 
     btnShowLocation.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View arg0) { 
       // create class object 
       gps = new GPSTracker(AndroidGPSTrackingActivity.this); 

       // check if GPS enabled 
       if(gps.canGetLocation()){ 

        double latitude = gps.getLatitude(); 
        double longitude = gps.getLongitude(); 

        // \n is for new line 
        Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show(); 
       }else{ 
        // can't get location 
        // GPS or Network is not enabled 
        // Ask user to enable GPS/network in settings 
        gps.showSettingsAlert(); 
       } 

      } 
     }); 
    } 


    } 

GPSTracker：

package com.example.muhammadshahid.smartsm; 

import android.app.Service; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.Intent; 
import android.content.pm.PackageManager; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Build; 
import android.os.Bundle; 
import android.os.IBinder; 
import android.provider.Settings; 
import android.support.v4.content.ContextCompat; 
import android.support.v7.app.AlertDialog; 
import android.util.Log; 

/** 
* Created by Muhammad Shahid on 2/23/2017. 
*/ 
public class GPSTracker extends Service implements LocationListener { 


    private final Context mContext; 

    // flag for GPS status 
    boolean isGPSEnabled = false; 

    // flag for network status 
    boolean isNetworkEnabled = false; 

    // flag for GPS status 
    boolean canGetLocation = false; 

    Location location; // location 
    double latitude; // latitude 
    double longitude; // longitude 

    // The minimum distance to change Updates in meters 
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters 

    // The minimum time between updates in milliseconds 
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute 

    // Declaring a Location Manager 
    protected LocationManager locationManager; 

    public GPSTracker(Context context) { 
     this.mContext = context; 
     getLocation(); 
    } 

    public Location getLocation() { 
     try { 
      locationManager = (LocationManager) mContext 
        .getSystemService(LOCATION_SERVICE); 

      // getting GPS status 
      isGPSEnabled = locationManager 
        .isProviderEnabled(LocationManager.GPS_PROVIDER); 

      // getting network status 
      isNetworkEnabled = locationManager 
        .isProviderEnabled(LocationManager.NETWORK_PROVIDER); 

      if (!isGPSEnabled && !isNetworkEnabled) { 
       // no network provider is enabled 
      } else { 
       this.canGetLocation = true; 
       // First get location from Network Provider 
       if (isNetworkEnabled) { 

        // check self permission 
        if (Build.VERSION.SDK_INT >= 23 && 
          ContextCompat.checkSelfPermission 
            (mContext, android.Manifest.permission.ACCESS_FINE_LOCATION) 
            != PackageManager.PERMISSION_GRANTED && 
          ContextCompat.checkSelfPermission 
            (mContext, android.Manifest.permission.ACCESS_COARSE_LOCATION) 
            != PackageManager.PERMISSION_GRANTED) { 
        } 


        locationManager.requestLocationUpdates(
          LocationManager.NETWORK_PROVIDER, 
          MIN_TIME_BW_UPDATES, 
          MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
        Log.d("Network", "Network"); 
        if (locationManager != null) { 
         location = locationManager 
           .getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 
         if (location != null) { 
          latitude = location.getLatitude(); 
          longitude = location.getLongitude(); 
         } 
        } 
       } 
       // if GPS Enabled get lat/long using GPS Services 
       if (isGPSEnabled) { 
        if (location == null) { 
         locationManager.requestLocationUpdates(
           LocationManager.GPS_PROVIDER, 
           MIN_TIME_BW_UPDATES, 
           MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
         Log.d("GPS Enabled", "GPS Enabled"); 
         if (locationManager != null) { 
          location = locationManager 
            .getLastKnownLocation(LocationManager.GPS_PROVIDER); 
          if (location != null) { 
           latitude = location.getLatitude(); 
           longitude = location.getLongitude(); 
          } 
         } 
        } 
       } 
      } 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 

     return location; 
    } 

    /** 
    * Stop using GPS listener 
    * Calling this function will stop using GPS in your app 
    * */ 
    public void stopUsingGPS() { 
     if (Build.VERSION.SDK_INT >= 23 && 
       ContextCompat.checkSelfPermission 
         (mContext, android.Manifest.permission.ACCESS_FINE_LOCATION) 
         != PackageManager.PERMISSION_GRANTED && 
       ContextCompat.checkSelfPermission 
         (mContext, android.Manifest.permission.ACCESS_COARSE_LOCATION) 
         != PackageManager.PERMISSION_GRANTED) 
     { 
      //requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_CODE_ASK_PERMISSIONS); 
     } 
      locationManager.removeUpdates(GPSTracker.this); 
     } 


    /** 
    * Function to get latitude 
    * */ 
    public double getLatitude(){ 
     if(location != null){ 
      latitude = location.getLatitude(); 
     } 

     // return latitude 
     return latitude; 
    } 

    /** 
    * Function to get longitude 
    * */ 
    public double getLongitude(){ 
     if(location != null){ 
      longitude = location.getLongitude(); 
     } 

     // return longitude 
     return longitude; 
    } 

    /** 
    * Function to check GPS/wifi enabled 
    * @return boolean 
    * */ 
    public boolean canGetLocation() { 
     return this.canGetLocation; 
    } 

    /** 
    * Function to show settings alert dialog 
    * On pressing Settings button will launch Settings Options 
    * */ 
    public void showSettingsAlert(){ 
     AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext); 

     // Setting Dialog Title 
     alertDialog.setTitle("GPS is settings"); 

     // Setting Dialog Message 
     alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?"); 

     // On pressing Settings button 
     alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() { 
      public void onClick(DialogInterface dialog,int which) { 
       Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
       mContext.startActivity(intent); 
      } 
     }); 

     // on pressing cancel button 
     alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
      public void onClick(DialogInterface dialog, int which) { 
       dialog.cancel(); 
      } 
     }); 

     // Showing Alert Message 
     alertDialog.show(); 
    } 

    @Override 
    public void onLocationChanged(Location location) { 
    } 

    @Override 
    public void onProviderDisabled(String provider) { 
    } 

    @Override 
    public void onProviderEnabled(String provider) { 
    } 

    @Override 
    public void onStatusChanged(String provider, int status, Bundle extras) { 
    } 

    @Override 
    public IBinder onBind(Intent arg0) { 
     return null; 
    } 


} 

Activity_tracker_xmlファイル：

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 

    xmlns:tools="http://schemas.android.com/tools" 
    android:id="@+id/activity_android_gpstracking" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 

    tools:context="com.example.muhammadshahid.smartsm.AndroidGPSTrackingActivity"> 


    <Button 
     android:text="ShowLocation" 
     android:id="@+id/btnShowLocation" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_marginTop="203dp" 
     android:layout_alignParentTop="true" 
     android:layout_centerHorizontal="true" /> 
</RelativeLayout> 

Minifest.xmlファイル：あなたは（ `クラスGPSTrackerがService`、その後` GPSは=新しいGPSTracker（...）を拡張 `Service`派生クラスにオペレータ` new`を使うべきではありません

Answer 1

setContentView(R.layout.activity_android_gpstracking); 

btnShowLocation = (Button) findViewById(R.id.btnShowLocation); 
//add this line you missing the button declaration