本文介绍了如何在我使用 Google 地图从当前位置开始移动时绘制路径的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
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遇到了一个大问题，请帮我解决它.我在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上画线.我没有两个固定点.任何人都可以为我提供一个解决方案来解决这个问题.我在 SO 中看到了很多答案，它们在两个固定点之间绘制了路径.但这里只有我的初始点是固定的.我目前能够在我的应用程序中获取我的当前位置.我尝试使用以下代码，但 getLocationManager() 导致错误.我正在使用 Android Studio.
I am trying to draw route as I move from my current location. I am facing a big problem in drawing route dynamically please help me to solve it. I am having marker at my current location in my map. As soon as I start moving I want the map to start drawing lines in the path I move. I do not have two fixed points. Can any one please provide me a solution to over come this. I have seen lot of answers in SO which draws path between two fixed points. But here only my initial point is fixed. I am able to get my current location in my app currently. I tried with the following code but getLocationManager() is resulting in error. i am using 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条，但它在 getLocationManager() 中给出错误；
I am trying to add this method in my code to draw line but its giving error in getLocationManager();
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) {
}
...
}
推荐答案
似乎最好的实现是只使用 ArrayList 来存储 onLocationChanged 中给出的每个点().然后，每次得到一个新点时，重新画线.
It seems that the best implementation would be to just use an ArrayList<LatLng> to store each point given in onLocationChanged(). Then, each time you get a new point, re-draw the line.
首先，导入绘制线条所需的内容:
First, import what you need for drawing the lines:
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
为 ArrayList 和折线创建成员变量:
Create member variables for the ArrayList and the Polyline:
private ArrayList<LatLng> points; //added
Polyline line; //added
在onCreate()中初始化points:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
points = new ArrayList<LatLng>(); //added
//...............
然后，在 onLocationChanged() 中，将获得的每个点添加到 ArrayList:
Then, in onLocationChanged(), add each point you get to the 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
}
取自 这个回答，定义你的 redrawLine() 方法.
删除对 addMarker() 的所有其他调用，因为您将在地图上调用 clear()，这会删除所有标记和折线.
Taking from this answer, define your redrawLine() method.
Remove all other calls to addMarker(), since you will be calling clear() on your map, which removes all Markers and Polylines.
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
}
您可能还希望在位置更改回调之间拨打以米为单位的最小距离.
You will also probably want to dial in the minimum distance in meters between location changed callbacks.
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
调用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);
}
这应该足以让您入门.您可能需要微调位置更改回调的频率以获得所需的结果.可能不止这些，但您可以找到边缘情况并在测试后修复它们.
That should be enough to get you started. You may need to fine-tune the frequency of location changed callbacks to get your desired result. There's probably more to it than that, but you can find the edge cases and fix them after testing.
这篇关于如何在我使用 Google 地图从当前位置开始移动时绘制路径的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！