android - 在Android文本框中打印经度和纬度

Question

我四处寻找，但找不到与我正在寻找的内容相关的任何直接线索。我正在尝试创建一个 Android 应用程序，按下按钮(我已经开始工作)拨出紧急号码，但无法显示位置(以经度和纬度显示)，我尝试使用 Toast 和编辑文本框。我是 Android 开发的新手，所以想从简单的开始，但 LongLat 部分很麻烦。任何帮助将不胜感激。

下面是我一直在篡改的代码，以便尝试让它获取经度和纬度，然后在另一个文件中，我一直在尝试使用点击监听器将其分配给一个按钮，所以当按钮是按下(在 main.xml 中)它将在文本字段或 toast 中显示 Long 和 Lat。

import android.app.Activity;
import android.location.Location;
import android.location.LocationListener;
import android.os.Bundle;
import android.widget.TextView;
import android.content.Context;
import android.location.LocationManager;
import android.location.Criteria;



        public class EmergencyLocation extends Activity implements LocationListener {
            private TextView latituteField;
            private TextView longitudeField;
            private LocationManager locationManager;
            private String provider;

            /** Called when the activity is first created. **/
            @Override
            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                latituteField = (TextView) findViewById(R.id.TextView);
                longitudeField = (TextView) findViewById(R.id.long_lat);

                // Get the location manager
                locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                // Define the criteria how to select the location provider -> use
                // default
                Criteria criteria = new Criteria();
                provider = locationManager.getBestProvider(criteria, false);
                Location location = locationManager.getLastKnownLocation(provider);

                // Initialise the location fields
                if (location != null) {
                    System.out.println("Provider " + provider + " has been selected.");
                    int lat = (int) (location.getLatitude());
                    int lng = (int) (location.getLongitude());
                    latituteField.setText(String.valueOf(lat));
                    longitudeField.setText(String.valueOf(lng));
                } else {
                    latituteField.setText("Provider not available");
                    longitudeField.setText("Provider not available");
                }
            }








        private void TextView() {
            // TODO Auto-generated method stub

        }


        @Override
        public void onLocationChanged(Location arg0) {
            // TODO Auto-generated method stub

        }


        @Override
        public void onProviderDisabled(String arg0) {
            // TODO Auto-generated method stub

        }


        @Override
        public void onProviderEnabled(String arg0) {
            // TODO Auto-generated method stub

        }


        @Override
        public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
            // TODO Auto-generated method stub

        }} 

Answer 1

首先，您需要设置一个LocationManager:

LocationManager manager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

// set preferred provider based on the best accuracy possible
Criteria fineAccuracyCriteria = new Criteria();
fineAccuracyCriteria.setAccuracy(Criteria.ACCURACY_FINE);
String preferredProvider = manager.getBestProvider(fineAccuracyCriteria, true);

现在，您必须创建一个 LocationListener。在这种情况下，它调用方法 updateLocation():

LocationListener listener = new LocationListener() {
        public void onLocationChanged(Location location) {
            // called when a new location is found by the network location provider.
            updateLocation(location);
        }

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

        public void onProviderEnabled(String provider) {}

        public void onProviderDisabled(String provider) {}
    };

编辑:

然后，您必须使用 LocationManager 注册监听器(并尝试获取缓存的位置):

manager.requestLocationUpdates(preferredProvider, 0, 0, listener);
// get a fast fix - cached version
updateLocation(manager.getLastKnownLocation());

最后，updateLocation() 方法:

private void updateLocation(Location location) {
    if (location == null)
        return;

    // save location details
    latitude = (float) location.getLatitude();
    longitude = (float) location.getLongitude();        
}

编辑 2:

好的，刚看到你的代码。为了让它工作，只需移动几位:

/** Called when the activity is first created. **/
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    latituteField = (TextView) findViewById(R.id.TextView);
    longitudeField = (TextView) findViewById(R.id.long_lat);

    // Get the location manager
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    // Define the criteria how to select the location provider -> use
    // default
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    locationManager.requestLocationUpdates(provider, 0, 0, this);
    Location location = locationManager.getLastKnownLocation(provider);
    onLocationChanged(location);
}

@Override
protected void onDestroy() {
    super.onDestroy();
    locationManager.removeUpdates(this);
}

@Override
public void onLocationChanged(Location location) {
   if (location != null) {
       System.out.println("Provider " + provider + " has been selected.");
       int lat = (int) (location.getLatitude());
       int lng = (int) (location.getLongitude());
       latituteField.setText(String.valueOf(lat));
       longitudeField.setText(String.valueOf(lng));
   } else {
       latituteField.setText("Provider not available");
       longitudeField.setText("Provider not available");
   }
}

希望对您有所帮助!