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我是安卓新手。我收到此错误:此行的构造函数 GpsData(btnReport) 未定义:

gps = new GpsData(btnReport.this);

编码:

public class btnReport extends AsyncTask<String, String, Void> {
    // GPSTracker class
    GpsData gps;

    @Override
    protected Void doInBackground(String... params) {
        String artID = params[0];

        // create class object
        gps = new GpsData(btnReport.this);

            double latitude = gps.getLatitude();
            double longitude = gps.getLongitude();
            String mlat = String.valueOf(latitude);
            String mlon = String.valueOf(longitude);

            // \n is for new line                  
            new PostData().execute(mlat, mlon, artID);

        gps.stopUsingGPS();
        return null;
    }

}

我能做些什么?

这是 GpsData:

public class GpsData 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 = 1000; // 1000 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 GpsData(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) { //! hinzugefuegt
                    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(locationManager != null){
            locationManager.removeUpdates(GpsData.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 lauch 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;
    }

}

好的,这是通过我的应用程序的方式:StartActivity:

        Intent intent = new Intent(StartActivity.this, ReportActivity.class);
        startActivity(intent);

报告活动:

public class ReportActivity extends Activity implements OnClickListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.report);
        Button b = (Button) findViewById(R.id.report_TJ_btn1);
        b.setOnClickListener(this);
        b = (Button) findViewById(R.id.report_TJ_btn2);
        b.setOnClickListener(this);
        b = (Button) findViewById(R.id.report_TJ_btn3);
        b.setOnClickListener(this);
    }
    @Override
    public void onClick(View v) {
        if(v.getId()== R.id.report_TJ_btn1) {
            startActivity(new Intent(this,btnReport.class));
        }
        if(v.getId()== R.id.report_TJ_btn2) {
            startActivity(new Intent(this,btnReport.class));
        }
        if(v.getId() == R.id.report_TJ_btn3) {
            startActivity(new Intent(this,btnReport.class));
        }
    }

}
4

2 回答 2

1

使用您的activityname.this(其中使用AsycTask)而不是您的btnReport.this.

public class btnReport extends AsyncTask<String, String, Void> {
        // GPSTracker class
        GpsData gps;

        @Override
        protected Void doInBackground(String... params) {
            String artID = params[0];

            MainActivity.this.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    gps = new GpsData(MainActivity.this);
                    double latitude = gps.getLatitude();
                    double longitude = gps.getLongitude();
                    String mlat = String.valueOf(latitude);
                    String mlon = String.valueOf(longitude);

                    // \n is for new line
                    // new PostData().execute(mlat, mlon, artID);

                    gps.stopUsingGPS();
                }
            });
            return null;
        }

    }
于 2012-11-21T09:43:29.740 回答
0

你需要将什么样的数据类型传递给'GpsData`的构造函数?

您正在向它传递一个实例,AsyncTask如果您想要一个Context而不是(这很常见),您可以尝试:

gps = new GpsData(Application.getContext());
于 2012-11-21T09:46:31.793 回答