当我从当前位置移动时，我正在尝试绘制路线。我在动态绘制路线时面临一个大问题请帮我解决。我在我的地图中的当前位置有标记。一旦我开始移动，我希望地图开始在我移动的路径中绘制线条。我没有两个固定点。任何人都可以为我提供解决方案。我在SO中看到很多答案，它在两个固定点之间绘制路径。但这里只有我的初步观点是固定的。我目前可以在我的应用中获取当前位置。我尝试使用以下代码，但getLocationManager（）导致错误。我正在使用Android Studio。
更新代码：
我的活动：
import android.content.Context;
import android.content.SharedPreferences;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.util.Xml;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.PendingResult;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.maps.android.ui.IconGenerator;
import org.xmlpull.v1.XmlSerializer;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.StringWriter;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Locale;
public class MainActivity extends FragmentActivity implements
LocationListener,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener {
private static final String TAG = "MainActivity";
private static final long INTERVAL = 1000 * 60 * 1; //1 minute
private static final long FASTEST_INTERVAL = 1000 * 60 * 1; // 1 minute
private LocationRequest mLocationRequest;
private GoogleApiClient mGoogleApiClient;
private Location mCurrentLocation;
private String mLastUpdateTime;
private String city = "";
private String country = "";
private String area = "";
private String title;
private String requiredArea = "";
private GoogleMap googleMap;
private List<Address> addresses;
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(INTERVAL);
mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate ...............................");
//show error dialog if GoolglePlayServices not available
if (!isGooglePlayServicesAvailable()) {
Toast.makeText(this, "Google Play Services is not available", Toast.LENGTH_LONG).show();
finish();
}
createLocationRequest();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
setContentView(R.layout.activity_main);
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
googleMap = fm.getMap();
googleMap.setMyLocationEnabled(true);
googleMap.setOnMyLocationButtonClickListener(new GoogleMap.OnMyLocationButtonClickListener() {
@Override
public boolean onMyLocationButtonClick() {
Toast.makeText(getApplicationContext(), "Location button has been clicked", Toast.LENGTH_LONG).show();
return true;
}
});
googleMap.getUiSettings().setZoomControlsEnabled(true);
googleMap.getUiSettings().setAllGesturesEnabled(true);
}
@Override
public void onStart() {
super.onStart();
Log.d(TAG, "onStart fired ..............");
mGoogleApiClient.connect();
}
@Override
public void onStop() {
super.onStop();
Log.d(TAG, "onStop fired ..............");
mGoogleApiClient.disconnect();
Log.d(TAG, "isConnected ...............: " + mGoogleApiClient.isConnected());
}
private boolean isGooglePlayServicesAvailable() {
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (ConnectionResult.SUCCESS == status) {
return true;
} else {
GooglePlayServicesUtil.getErrorDialog(status, this, 0).show();
Toast.makeText(getApplicationContext(), "Google Play Services is not Available", Toast.LENGTH_LONG).show();
return false;
}
}
@Override
public void onConnected(Bundle bundle) {
Log.d(TAG, "onConnected - isConnected ...............: " + mGoogleApiClient.isConnected());
startLocationUpdates();
}
protected void startLocationUpdates() {
PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
Log.d(TAG, "Location update started ..............: ");
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.d(TAG, "Connection failed: " + connectionResult.toString());
}
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "Firing onLocationChanged..............................................");
mCurrentLocation = location;
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
addMarker();
float accuracy = location.getAccuracy();
Log.d("iFocus", "The amount of accuracy is " + accuracy);
double latitude = location.getLatitude();
double longitude = location.getLongitude();
Bundle extras = location.getExtras();
Boolean has = location.hasAccuracy();
String provider = location.getProvider();
Long time = location.getTime();
// Location locationB = new Location("Begur");
// double lati = 12.8723;
// double longi = 77.6329;
// locationB.setLatitude(lati);
// locationB.setLongitude(longi);
// Float distance = location.distanceTo(locationB);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(time);
int mYear = calendar.get(Calendar.YEAR);
int mMonth = calendar.get(Calendar.MONTH) + 1;
int mDay = calendar.get(Calendar.DAY_OF_MONTH);
String formattedTime = mDay + ":" + mMonth + ":" + mYear;
Log.d("iFocus", "The name of provider is " + provider);
Log.d("iFocus", "The value of has is " + has);
Log.d("iFocus", "The value of extras is " + extras);
Log.d("iFocus", "The value of Month is " + mMonth);
Log.d("iFocus", "The value of Day is " + mDay);
Log.d("iFocus", "The value of Year is " + mYear);
Log.d("iFocus", "The value of Time is " + formattedTime);
//Log.d("iFocus", "The value of distance is "+distance);
LatLng latLng = new LatLng(latitude, longitude);
Geocoder geocoder = new Geocoder(this, Locale.getDefault());
try {
addresses = geocoder.getFromLocation(latitude, longitude, 1);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String cityName = addresses.get(0).getAddressLine(0);
String stateName = addresses.get(0).getAddressLine(1);
String countryName = addresses.get(0).getAddressLine(2);
String[] splittedStateName = stateName.split(",");
requiredArea = splittedStateName[2];
Log.d("iFocus", "The value of required area is " + requiredArea);
city = addresses.get(0).getLocality();
area = addresses.get(0).getSubLocality();
String adminArea = addresses.get(0).getAdminArea();
String premises = addresses.get(0).getPremises();
String subAdminArea = addresses.get(0).getSubAdminArea();
String featureName = addresses.get(0).getFeatureName();
String phone = addresses.get(0).getPhone();
country = addresses.get(0).getCountryName();
Log.d("iFocus", "The name of city is " + city);
Log.d("iFocus", "The name of area is " + area);
Log.d("iFocus", "The name of country is " + country);
Log.d("iFocus", "The value of cityName is " + cityName);
Log.d("iFocus", "The value of StateName is " + stateName);
Log.d("iFocus", "The value of CountryName is " + countryName);
Toast.makeText(this, cityName + " " + stateName + " " + countryName, Toast.LENGTH_LONG).show();
SharedPreferences sharedPreferences = getSharedPreferences("MyValues", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("CITY", cityName);
editor.putString("STATE", stateName);
editor.putString("COUNTRY", countryName);
editor.commit();
TextView mapTitle = (TextView) findViewById(R.id.textViewTitle);
if (requiredArea != "" && city != "" && country != "") {
title = mLastUpdateTime.concat(", " + requiredArea).concat(", " + city).concat(", " + country);
}
else {
title = mLastUpdateTime.concat(", " + area).concat(", " + city).concat(", " + country);
}
mapTitle.setText(title);
addMarker();// newly added
final String xmlFile = "userData.xml";
try {
// FileOutputStream fos = new FileOutputStream("userData.xml");
FileOutputStream fos = openFileOutput(xmlFile, Context.MODE_PRIVATE);
XmlSerializer xmlSerializer = Xml.newSerializer();
StringWriter writer = new StringWriter();
xmlSerializer.setOutput(writer);
xmlSerializer.startDocument("UTF-8", true);
xmlSerializer.startTag(null, "userData");
xmlSerializer.startTag(null, "Time");
xmlSerializer.text(mLastUpdateTime);
xmlSerializer.endTag(null, "Time");
xmlSerializer.startTag(null, "Area");
if (requiredArea != "") {
xmlSerializer.text(requiredArea);
}
else {
xmlSerializer.text(area);
}
xmlSerializer.endTag(null, "Area");
xmlSerializer.startTag(null, "City");
xmlSerializer.text(city);
xmlSerializer.endTag(null, "City");
xmlSerializer.endTag(null, "userData");
xmlSerializer.endDocument();
xmlSerializer.flush();
String dataWrite = writer.toString();
fos.write(dataWrite.getBytes());
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String dir = getFilesDir().getAbsolutePath();
Log.d("Pana", "The value of Dir is "+dir);
}
private void addMarker() {
MarkerOptions options = new MarkerOptions();
// following four lines requires 'Google Maps Android API Utility Library'
// https://developers.google.com/maps/documentation/android/utility/
// I have used this to display the time as title for location markers
// you can safely comment the following four lines but for this info
IconGenerator iconFactory = new IconGenerator(this);
iconFactory.setStyle(IconGenerator.STYLE_PURPLE);
// options.icon(BitmapDescriptorFactory.fromBitmap(iconFactory.makeIcon(mLastUpdateTime + requiredArea + city)));
options.icon(BitmapDescriptorFactory.fromBitmap(iconFactory.makeIcon(requiredArea + ", " + city)));
options.anchor(iconFactory.getAnchorU(), iconFactory.getAnchorV());
LatLng currentLatLng = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
options.position(currentLatLng);
Marker mapMarker = googleMap.addMarker(options);
long atTime = mCurrentLocation.getTime();
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date(atTime));
String title = mLastUpdateTime.concat(", " + requiredArea).concat(", " + city).concat(", " + country);
mapMarker.setTitle(title);
TextView mapTitle = (TextView) findViewById(R.id.textViewTitle);
mapTitle.setText(title);
Log.d(TAG, "Marker added.............................");
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(currentLatLng,
13));
Log.d(TAG, "Zoom done.............................");
}
@Override
protected void onPause() {
super.onPause();
stopLocationUpdates();
}
protected void stopLocationUpdates() {
LocationServices.FusedLocationApi.removeLocationUpdates(
mGoogleApiClient, this);
Log.d(TAG, "Location update stopped .......................");
}
@Override
public void onResume() {
super.onResume();
if (mGoogleApiClient.isConnected()) {
startLocationUpdates();
Log.d(TAG, "Location update resumed .....................");
}
}
}
我正在尝试在我的代码中添加此方法来绘制线但在getLocationManager（）中给出错误;
private void addLocationListener(LocationListener locationListener) {
LocationProvider locationProvider = getLocationManager().getProvider(LocationManager.GPS_PROVIDER);
getLocationManager().requestLocationUpdates(locationProvider.getName(), LOCATION_UPDATE_INTERVAL,
LOCATION_UPDATE_MIN_DISTANCE, locationListener);
}
private LocationManager getLocationManager() {
return (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
}
private void startGpsListening(Location start) {
this.startLocation = start;
addLocationListener(new MyLocationListener());
}
private Location startLocation = new Location("");
private class MyLocationListener extends LocationListener {
public void onLocationChanged(Location location) {
}
...
}
答案 0 :(得分：31)
似乎最好的实现方法是使用ArrayList<LatLng>来存储onLocationChanged()中给出的每个点。然后，每次获得新点时，重新绘制线条。
首先，导入绘制线条所需的内容：
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
为ArrayList和Polyline创建成员变量：
private ArrayList<LatLng> points; //added
Polyline line; //added
在points中初始化onCreate()：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
points = new ArrayList<LatLng>(); //added
//...............
然后，在onLocationChanged()中，将您获得的每个点添加到ArrayList：
@Override
public void onLocationChanged(Location location) {
double latitude = location.getLatitude();
double longitude = location.getLongitude();
LatLng latLng = new LatLng(latitude, longitude); //you already have this
points.add(latLng); //added
redrawLine(); //added
}
从this answer开始，定义您的redrawLine()方法
移除对addMarker()的所有其他来电，因为您将在地图上调用clear()，这会删除所有标记和折线。
private void redrawLine(){
googleMap.clear(); //clears all Markers and Polylines
PolylineOptions options = new PolylineOptions().width(5).color(Color.BLUE).geodesic(true);
for (int i = 0; i < points.size(); i++) {
LatLng point = points.get(i);
options.add(point);
}
addMarker(); //add Marker in current position
line = googleMap.addPolyline(options); //add Polyline
}
编辑：您可能还希望拨打位置更改回调之间的最小距离（以米为单位）。
private static final String TAG = "MainActivity";
private static final long INTERVAL = 1000 * 60 * 1; //1 minute
private static final long FASTEST_INTERVAL = 1000 * 60 * 1; // 1 minute
private static final float SMALLEST_DISPLACEMENT = 0.25F; //quarter of a meter
致电setSmallestDisplacement()：
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(INTERVAL);
mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
mLocationRequest.setSmallestDisplacement(SMALLEST_DISPLACEMENT); //added
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
这应该足以让你入门。您可能需要微调位置更改回调的频率以获得所需的结果。可能还有更多，但你可以找到边缘情况并在测试后修复它们。
答案 1 :(得分：2)
我知道答案已经很晚了，但是我会在这里发布这个问题仍然存在同样问题。
如果要移动标记或/和折线，则无需删除/清除并再次绘制，而是必须添加一次PolylineOptions，然后再设置新点。
示例代码：
boolean isPolyAdded = false;
添加以下代码行：
if (isPolyLoaded == false){
polyline = map.addPolyline(lineOptions);
isPolyLoaded = true;
}else{
polyline.setPoints(points);
}
到onPostExecute方法
最终代码：
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
// Traversing through all the routes
for(int i=0;i<result.size();i++){
points = new ArrayList<LatLng>();
lineOptions = new PolylineOptions();
// Fetching i-th route
List<HashMap<String, String>> path = result.get(i);
// Fetching all the points in i-th route
for(int j=0;j<path.size();j++){
HashMap<String,String> point = path.get(j);
double lat = Double.parseDouble(point.get("lat"));
double lng = Double.parseDouble(point.get("lng"));
LatLng position = new LatLng(lat, lng);
points.add(position);
}
// Adding all the points in the route to LineOptions
lineOptions.addAll(points);
lineOptions.width(7);
lineOptions.color(Color.BLACK);
}
// Drawing polyline in the Google Map for the i-th route
if (isPolyLoaded == false){
polyline = map.addPolyline(lineOptions);
isPolyLoaded = true;
}else{
polyline.setPoints(points);
}
}
}
答案 2 :(得分：0)
在移动时绘制折线非常简单
第1步：创建折线变量，以供参考更新，如下所示
private Polyline polyline_path;
第2步：在MapReady回调上，如下所示
PolylineOptions routes = new PolylineOptions().width(5).color(Color.BLUE);
polyline_path = mMap.addPolyline(routes);
Step3：在新位置上，您通过将点发送到 这种方法
private void UpdatePoints(LatLng newlatlng) {
List<LatLng> points = polyline_path.getPoints();
points.add(newlatlng);
polyline_path.setPoints(points);
}