我想要实现的是点击后显示方向的按钮。 我应该如何放置标记？从导航仪显示的当前位置位置显示正确方法的方法是什么。
这是我的MapsActivity，我已经在其中声明了我需要的一些特定功能。
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {
private GoogleMap mMap;
private static final String TAG = MapsActivity.class.getSimpleName();
LocationManager locationManager;
LocationRequest mLocationRequest;
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
Marker mCurrLocationMarker;
Button logoutButton;
private FirebaseAuth.AuthStateListener mAuthListener;
private FirebaseAuth mAuth;
private GoogleSignInClient mGoogleSignInClient;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View decor_View = getWindow().getDecorView();
int ui_Options = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
decor_View.setSystemUiVisibility(ui_Options);
UiChangeListener();
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
mAuth = FirebaseAuth.getInstance();
logoutButton = (Button) findViewById(R.id.logoutButton);
logoutButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
signOut();
Intent intent = new Intent(MapsActivity.this, SignInActivity.class);
startActivity(intent);
finish();
}
});
mAuth = FirebaseAuth.getInstance();
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
if (firebaseAuth.getCurrentUser() == null) {
startActivity(new Intent(MapsActivity.this, SignInActivity.class));
}
}
};
}
@Override
protected void onPause() {
super.onPause();
if (mGoogleApiClient != null) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
private void signOut() {
mAuth.signOut();
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.getUiSettings().setMapToolbarEnabled(false);
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
//Location Permission already granted
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
} else {
//Request Location Permission
checkLocationPermission();
}
} else {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
try {
// Customise the styling of the base map using a JSON object defined
// in a raw resource file.
boolean success = googleMap.setMapStyle(
MapStyleOptions.loadRawResourceStyle(
this, R.raw.custom_google_map));
if (!success) {
Log.e(TAG, "Style parsing failed.");
}
} catch (Resources.NotFoundException e) {
Log.e(TAG, "Can't find style. Error: ", e);
}
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;
}
Marker marker = mMap.addMarker(new MarkerOptions()
.position(new LatLng(51.1117744, 17.0353596))
.title("Giselle French Bakery Cafe")
.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)));
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mGoogleApiClient.connect();
}
@Override
public void onConnected(@Nullable Bundle bundle) {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(20 * 1000);
mLocationRequest.setFastestInterval(20 * 1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
mLastLocation = location;
if (mCurrLocationMarker != null) {
mCurrLocationMarker.remove();
}
//Place current location marker
LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title("You are here");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_BLUE));
mCurrLocationMarker = mMap.addMarker(markerOptions);
//move map camera
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 18));
}
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
private void checkLocationPermission() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
new AlertDialog.Builder(this)
.setTitle("Location Permission Needed")
.setMessage("This app needs the Location permission, please accept to use location functionality")
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(MapsActivity.this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
})
.create()
.show();
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// location-related task you need to do.
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
if (mGoogleApiClient == null) {
buildGoogleApiClient();
}
mMap.setMyLocationEnabled(true);
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
public void UiChangeListener() {
final View decorView = getWindow().getDecorView();
decorView.setOnSystemUiVisibilityChangeListener(new View.OnSystemUiVisibilityChangeListener() {
@Override
public void onSystemUiVisibilityChange(int visibility) {
if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
decorView.setSystemUiVisibility(
View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
}
}
});
}
}
希望有人能回答我如何实现这一目标:)
答案 0 :(得分：0)
由于您没有指定要显示路线的位置，但是您已经在java代码中实现了位置，我假设您要显示当前位置和点击标记之间的路线。
首先，转到我的回答here并创建距离，时间和方向所需的所有三个java文件。
然后，在程序中实现onMarkerClick，如下所示：
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener, GoogleMap.OnMarkerClickListener {
.
.
.
@Override
public void onMapReady(GoogleMap mMap){
.
.
.
map.setOnMarkerClickListener(this);
.
.
.
}
@Override
public boolean onMarkerClick(final Marker marker) {
LatLng latLng = new LatLng(mLastLocation.getLatitude(), mLastLocation.getLongitude());
distance_task.getDirectionsUrl(latLng, marker.getPosition());
distance_task.setLoadListener(new CalculateDistanceTime.taskCompleteListener() {
@Override
public void taskCompleted(String[] time_distance) {
text1.setText(time_distance[0]); //Distance
text2.setText(time_distance[1]); //Time
}
});
String url = getDirectionsUrl(latLng, marker.getPosition());
DownloadTask downloadTask = new DownloadTask();
downloadTask.execute(url);
}
.
.
.
}
上面的代码将为您提供这两个点（您的位置，标记），时间（使用汽车）和折线之间的距离，并自行实现折线，但请记住通过两个Textview（ text1和text2）设置它将显示错误的距离和时间。
此外，如果您只想要路线，那么只使用DirectionsJSONParser.java，而只使用onMarkerClick中上面代码的最后三行。
这肯定会起作用，因为我使用相同的方式，但您还需要考虑一些额外的事情，让您的应用顺利运行而不会崩溃。其中一些问题是此代码只应在mLastLocation不为null，有互联网连接，GPS打开等时执行。此外，在点击任何其他标记时，应删除之前的路径等。
编辑：（直接从我的项目中复制）
声明两个全局变量
Polyline lastPolyline;
boolean isSecond = false;
然后在类ParserTask中的onPostExecute（）方法：
用
替换googleMap.addPolyline(lineOptions);
if (isSecond) {
lastPolyline.remove();
lastPolyline = googleMap.addPolyline(lineOptions);
}
else {
lastPolyline = googleMap.addPolyline(lineOptions);
isSecond = true;
}