我的要求非常简单。
我想获取用户的位置并在屏幕上显示相同内容。
模拟器正确显示当前报告的位置。但是我无法将其提取到TextView中。不太清楚这里有什么问题。
请在下面找到我的代码。帮助赞赏。
MainActivity.java
package com.varun.weatherbee;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import java.util.List;
public class MainActivity extends AppCompatActivity implements LocationListener {
private final static String TAG = MainActivity.class.getSimpleName();
TextView mLongitudeText;
TextView mLatitudeText;
LocationManager locationManager;
Location location;
double latitude;
double longitutde;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mLatitudeText = (TextView) findViewById(R.id.mLatitudeText);
mLongitudeText = (TextView) findViewById(R.id.mLongitudeText);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
List<String> providers = locationManager.getAllProviders();
for (int i = 0; i < providers.size(); i++) {
Log.i(TAG, providers.get(i));
}
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
Log.i(TAG, "Permission Granted");
return;
}
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
mLatitudeText.setText("Latitude: " + location.getLatitude());
mLongitudeText.setText("Longitude: " + location.getLongitude());
}
}
@Override
protected void onStart() {
super.onStart();
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 1000, this);
}
@Override
protected void onStop() {
super.onStop();
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.removeUpdates(this);
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
答案 0 :(得分：1)
试试这段代码：
1.您的运行时permission检查错误
2.另外getLastKnownLocation(LocationManager.GPS_PROVIDER)可以返回null See here
3.您可以使用textview方法
onLocationChanged()
这是一个简单的例子：
public class MainActivity extends AppCompatActivity implements LocationListener {
private final static String TAG = MainActivity.class.getSimpleName();
TextView mLongitudeText;
TextView mLatitudeText;
LocationManager locationManager;
Location location;
double latitude;
double longitutde;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mLatitudeText = (TextView) findViewById(R.id.mLatitudeText);
mLongitudeText = (TextView) findViewById(R.id.mLongitudeText);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
List<String> providers = locationManager.getAllProviders();
for (int i = 0; i < providers.size(); i++) {
Log.i(TAG, providers.get(i));
}
//location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (isLocationPermissionGranted()) {
location = getLastKnownLocation();
if (location != null) {
mLatitudeText.setText("Latitude: " + location.getLatitude());
mLongitudeText.setText("Longitude: " + location.getLongitude());
}
}
}
private Location getLastKnownLocation() {
locationManager = (LocationManager) getApplicationContext().getSystemService(LOCATION_SERVICE);
List<String> providers = locationManager.getProviders(true);
Location bestLocation = null;
for (String provider : providers) {
Location l = locationManager.getLastKnownLocation(provider);
if (l == null) {
continue;
}
if (bestLocation == null || l.getAccuracy() < bestLocation.getAccuracy()) {
// Found best last known location: %s", l);
bestLocation = l;
}
}
return bestLocation;
}
@Override
protected void onStart() {
super.onStart();
if (isLocationPermissionGranted())
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 1000, this);
}
@Override
protected void onStop() {
super.onStop();
locationManager.removeUpdates(this);
}
@Override
public void onLocationChanged(Location location) {
mLatitudeText.setText("Latitude: " + location.getLatitude());
mLongitudeText.setText("Longitude: " + location.getLongitude());
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
public boolean isLocationPermissionGranted() {
if (Build.VERSION.SDK_INT >= 23) {
if (checkSelfPermission(android.Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
Log.v(TAG, "Permission is granted");
return true;
} else {
Log.v(TAG, "Permission is revoked");
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
return false;
}
} else { //permission is automatically granted on sdk<23 upon installation
Log.v(TAG, "Permission is granted");
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.v(TAG, "Permission: " + permissions[0] + "was " + grantResults[0]);
//resume tasks needing this permission
}
}
}