使用Criteria.ACCURACY_COARSE我可以找到位置,但是它不准确。我想使用GPS Criteria.ACCURACY_FINE,但未调用onLocationChanged(Location location)方法。
我做了一些研究,但不知道为什么。
关于StackOverflow,有很多类似的问题,但是不幸的是,我找不到一个可以解决我问题的方法。
下面是我的源代码:

private void locationInformationSettings(){
    Criteria criteria= new  Criteria();;
    criteria.setAccuracy(Criteria.ACCURACY_FINE); //using Criteria.ACCURACY_COARSE works
    //criteria.setPowerRequirement(Criteria.POWER_LOW);

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    String providername = locationManager.getBestProvider(criteria, true);

    myLocationListener = new MyLocationListener();

    locationManager.requestLocationUpdates(
            providername, //LocationManager.GPS_PROVIDER,
            Utils.MINIMUM_TIME_BETWEEN_UPDATES,
            Utils.MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
            myLocationListener
    );
}

private class MyLocationListener implements LocationListener {

    public void onLocationChanged(Location location) {

        locLongitude = location.getLongitude();
        locLatitude = location.getLatitude();
        String message = String.format(
                "New Location \n Longitude: %1$s \n Latitude: %2$s",
                locLongitude, locLatitude);
        Toast.makeText(RecordActivity.this, message, Toast.LENGTH_LONG).show();
        Log.e(TAG, "Location information received:(" + locLongitude + "," + locLatitude +")");
        locationManager.removeUpdates(myLocationListener);
    }

    public void onStatusChanged(String s, int i, Bundle b) {
        Toast.makeText(RecordActivity.this, "Provider status changed",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderDisabled(String s) {
        Toast.makeText(RecordActivity.this,
                "Provider disabled by the user. GPS turned off",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderEnabled(String s) {
        Toast.makeText(RecordActivity.this,
                "Provider enabled by the user. GPS turned on",
                Toast.LENGTH_LONG).show();
    }

}


清单文件权限:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />


为什么使用网络提供商有效而GPS提供商无效?
我已经检查了设备上的GPS服务设置,并在Android 4.3和Android 2.3.3上进行了测试。

提前致谢

最佳答案

干得好

package com.test.locationmanager;

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

public class LocationManagerStatus extends Activity {

private LocationManager locationManager;
private TextView textView;
private final LocationListener gpsLocationListener = new LocationListener() {

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        final String tvTxt = textView.getText().toString();
        switch (status) {
        case LocationProvider.AVAILABLE:
            textView.setText(tvTxt + "GPS available again\n");
            break;
        case LocationProvider.OUT_OF_SERVICE:
            textView.setText(tvTxt + "GPS out of service\n");
            break;
        case LocationProvider.TEMPORARILY_UNAVAILABLE:
            textView.setText(tvTxt + "GPS temporarily unavailable\n");
            break;
        }
    }

    @Override
    public void onProviderEnabled(String provider) {
        textView.setText(textView.getText().toString()
                + "GPS Provider Enabled\n");
    }

    @Override
    public void onProviderDisabled(String provider) {
        textView.setText(textView.getText().toString()
                + "GPS Provider Disabled\n");
    }

    @Override
    public void onLocationChanged(Location location) {
        locationManager.removeUpdates(networkLocationListener);
        textView.setText(textView.getText().toString()
                + "New GPS location: "
                + String.format("%9.6f", location.getLatitude()) + ", "
                + String.format("%9.6f", location.getLongitude()) + "\n");
    }
};
private final LocationListener networkLocationListener = new LocationListener() {

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        final String tvTxt = textView.getText().toString();
        switch (status) {
        case LocationProvider.AVAILABLE:
            textView.setText(tvTxt + "Network location available again\n");
            break;
        case LocationProvider.OUT_OF_SERVICE:
            textView.setText(tvTxt + "Network location out of service\n");
            break;
        case LocationProvider.TEMPORARILY_UNAVAILABLE:
            textView.setText(tvTxt
                    + "Network location temporarily unavailable\n");
            break;
        }
    }

    @Override
    public void onProviderEnabled(String provider) {
        textView.setText(textView.getText().toString()
                + "Network Provider Enabled\n");
    }

    @Override
    public void onProviderDisabled(String provider) {
        textView.setText(textView.getText().toString()
                + "Network Provider Disabled\n");
    }

    @Override
    public void onLocationChanged(Location location) {
        textView.setText(textView.getText().toString()
                + "New network location: "
                + String.format("%9.6f", location.getLatitude()) + ", "
                + String.format("%9.6f", location.getLongitude()) + "\n");
    }
};

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    textView = (TextView) findViewById(R.id.textview);
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}

@Override
protected void onResume() {
    super.onResume();
    locationManager.requestLocationUpdates(
            LocationManager.NETWORK_PROVIDER, 5000, 0,
            networkLocationListener);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
            3000, 0, gpsLocationListener);
}

@Override
protected void onPause() {
    super.onPause();
    locationManager.removeUpdates(networkLocationListener);
    locationManager.removeUpdates(gpsLocationListener);
}
}

07-28 03:34
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