我想显示当前位置的纬度，经度，并在三个文本视图中显示该地点的纬度和经度的位置名称。但是在tv_lat和tv_long中没有显示纬度和经度值。
public class MainActivity extends AppCompatActivity implements NetworkCallback, LocationListener {
private EditText empIdTxt;
private EditText passwordTxt;
private TextView tv_lat;
private TextView tv_long;
private TextView tv_place;
private Button loginBtn;
protected Location mLastLocation;
LocationManager locationmanager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
empIdTxt = (EditText) findViewById(R.id.et_loginId);
passwordTxt = (EditText) findViewById(R.id.et_loginPass);
tv_lat = (TextView) findViewById(R.id.tv_lat);
tv_long = (TextView) findViewById(R.id.tv_long);
tv_place = (TextView) findViewById(R.id.tv_place);
loginBtn = (Button) findViewById(R.id.bt_login);
empIdTxt.addTextChangedListener(new MyTextWatcher(empIdTxt));
passwordTxt.addTextChangedListener(new MyTextWatcher(passwordTxt));
empIdTxt.setText("vinay");
passwordTxt.setText("qwerty");
locationmanager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria cri = new Criteria();
String provider = locationmanager.getBestProvider(cri, false);
if (provider != null & !provider.equals("")) {
Location location = locationmanager.getLastKnownLocation(provider);
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 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(provider, 2000, 1, this);
if(location!=null) {
onLocationChanged(location);
}else{
Toast.makeText(getApplicationContext(),"location not found",Toast.LENGTH_LONG ).show();
}
}else{
Toast.makeText(getApplicationContext(),"Provider is null",Toast.LENGTH_LONG).show();
}
}
public void clickLogin(View v) {
if (!validateEmpID()) {
return;
}
if (!validatePassword()) {
return;
}
LoginApi api = new LoginApi(this, this);
api.processLogin(empIdTxt.getText().toString(), passwordTxt.getText().toString(),
mLastLocation.getLatitude()+"",mLastLocation.getLongitude()+"",
AlertDialogManager.todayDate(), new GPSTracker(MainActivity.this).getLocation()+"");
}
private void requestFocus(View view) {
if (view.requestFocus()) {
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
}
}
private boolean validateEmpID() {
if (empIdTxt.getText().toString().trim().isEmpty()) {
empIdTxt.setError(ErrorUtil.USERNAME_ERROR);
requestFocus(empIdTxt);
return false;
}
return true;
}
private boolean validatePassword() {
if (passwordTxt.getText().toString().trim().isEmpty()) {
passwordTxt.setError(ErrorUtil.PASSWORD_ERROR);
requestFocus(passwordTxt);
return false;
}
return true;
}
private class MyTextWatcher implements TextWatcher {
private View view;
private MyTextWatcher(View view) {
this.view = view;
}
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
public void afterTextChanged(Editable editable) {
switch (view.getId()) {
case R.id.et_loginId:
validateEmpID();
break;
case R.id.et_loginPass:
validatePassword();
break;
}
}
}
@Override
public void updateScreen(String data, String tag) {
if (tag.compareTo(ApiUtil.TAG_LOGIN) == 0) {
try {
System.out.println("Login Response"+data);
JSONObject mainObj = new JSONObject(data);
AppDelegate ctrl = AppDelegate.getInstance();
if (!mainObj.isNull("username")) {
ctrl.username = mainObj.getString("username");
}
if (!mainObj.isNull("password")) {
ctrl.password = mainObj.getString("password");
}
/* if (!mainObj.isNull("latitude")) {
ctrl.password = mainObj.getString("latitude");
}
if (!mainObj.isNull("longitude")) {
ctrl.password = mainObj.getString("longitude");
}
if (!mainObj.isNull("date_and_time")) {
ctrl.password = mainObj.getString("date_and_time");
}
if (!mainObj.isNull("place")) {
ctrl.password = mainObj.getString("place");
}*/
if (!mainObj.isNull("error")) {
Toast.makeText(MainActivity.this,"Login Fails",Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this,"Login Success",Toast.LENGTH_SHORT).show();
}
} catch (Exception e) {
Toast.makeText(MainActivity.this,"Seems there is an issue please try again later",Toast.LENGTH_SHORT).show();
}
}
}
@Override
public void onLocationChanged(Location location) {
tv_lat.setText("Latitude"+location.getLatitude());
tv_long.setText("Longitude"+ location.getLongitude());
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
}
答案 0 :(得分：0)
确保您已在清单中获得此权限。你的gps应该打开：
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
如果您在棉花糖中测试您的应用程序：
以编程方式授予权限。
最后一件事是从您的代码中删除此条件并运行它。它一定会奏效：
删除它：
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 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;
}
如果您发现它无法正常工作，我会发布自己的课程，该课程在Lollipop上完美运行，请检查：
public class Google_Map_Current_Location extends FragmentActivity implements LocationListener {
GoogleMap googleMap;
Location location;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//show error dialog if GoolglePlayServices not available
if (!isGooglePlayServicesAvailable()) {
finish();
}
setContentView(R.layout.google_map_current_loction);
SupportMapFragment supportMapFragment =
(SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.googleMap);
googleMap = supportMapFragment.getMap();
try {
googleMap.setMyLocationEnabled(true);
} catch (Exception e) {
e.printStackTrace();
}
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
showSettingsAlert();
}
Criteria criteria = new Criteria();
String bestProvider = locationManager.getBestProvider(criteria, true);
try {
location = locationManager.getLastKnownLocation(bestProvider);
} catch (Exception e) {
e.printStackTrace();
}
if (location != null) {
onLocationChanged(location);
}
try {
locationManager.requestLocationUpdates(bestProvider, 20000, 0, this);
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void onLocationChanged(Location location) {
TextView locationTv = (TextView) findViewById(R.id.latlongLocation);
double latitude = location.getLatitude();
double longitude = location.getLongitude();
LatLng latLng = new LatLng(latitude, longitude);
googleMap.addMarker(new MarkerOptions().position(latLng));
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
googleMap.animateCamera(CameraUpdateFactory.zoomTo(15));
locationTv.setText("Latitude:" + latitude + ", Longitude:" + longitude);
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
private boolean isGooglePlayServicesAvailable() {
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (ConnectionResult.SUCCESS == status) {
return true;
} else {
GooglePlayServicesUtil.getErrorDialog(status, this, 0).show();
return false;
}
}
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
// 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);
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();
}