我是Android开发中的新手，并在Android应用程序上工作，我正在使用谷歌地图以及wikimapia请求api。我在屏幕上显示一些按钮让我们说警察，医院，地铁。当我点击按钮时，请说＆＃34;警察＆＃34;它发送wikimapia请求，标记显示在地图上，但当我点击＆＃34;医院＆＃34;它还向我展示了医院标记，但还有警察标记。我还使用了地图的clear()，但它清除了整个地图。我需要在屏幕上显示我点击的标记并删除其他标记。我的代码如下，请在这里帮助我。
public class MyLocationActivity extends BaseActivity implements
OnMapClickListener, OnMapLongClickListener, NetworkStateReceiverListener{
private GoogleMap mMap;
private Location lastLocation = null;
private LocationClient mLocationClient;
public AlertDialog alert;
DocumentBuilder documentBuilder;
Document document;
private NetworkStateReceiver networkStateReceiver;
boolean connectionStatus = false;
final MarkerOptions markerOptions = new MarkerOptions();
private static final LocationRequest REQUEST = LocationRequest.create()
.setInterval(8000) // 5 seconds
.setFastestInterval(16) // 16ms = 60fps
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
@Override
protected void onStart() {
sActivityMyLocation = this;
super.onStart();
}
@Override
protected void onDestroy() {
sActivityMyLocation = null;
mMap.clear();
//unregisterReceiver(networkStateReceiver);
super.onDestroy();
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_location_hospitals);
networkStateReceiver = new NetworkStateReceiver();
networkStateReceiver.addListener(this);
this.registerReceiver(networkStateReceiver, new IntentFilter(android.net.ConnectivityManager.CONNECTIVITY_ACTION));
ImageView imgHospital = (ImageView) findViewById(R.id.imgHospital);
imgHospital.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
new PlacesAPICall().execute();
}
});
ImageView imgPolice = (ImageView) findViewById(R.id.imgPolice);
imgPolice.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
new PlacesAPICall().execute();
}
});
ImageView imgMetro = (ImageView) findViewById(R.id.imgMetro);
imgMetro.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
new PlacesAPICall().execute();
}
});
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
setUpLocationClientIfNeeded();
mLocationClient.connect();
}
@Override
public void onPause() {
super.onPause();
if (mLocationClient != null) {
mLocationClient.disconnect();
}
}
private void setUpMapIfNeeded() {
if (mMap == null) {
mMap = ((SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map)).getMap();
mMap.setOnMapClickListener(MyLocationActivity.this);
if (mMap != null) {
mMap.setOnMapClickListener(MyLocationActivity.this);
mMap.setMyLocationEnabled(true);
mMap.setBuildingsEnabled(true);
mMap.setIndoorEnabled(true);
mMap.setMapType(mMap.MAP_TYPE_NORMAL);
mMap.setTrafficEnabled(true);
}
}
}
private void setUpLocationClientIfNeeded() {
if (mLocationClient == null) {
mLocationClient = new LocationClient(getApplicationContext(),
connectionCallbacks, onConnectionFailedListener);
}
}
ConnectionCallbacks connectionCallbacks = new ConnectionCallbacks() {
@Override
public void onDisconnected() {
}
@Override
public void onConnected(Bundle connectionHint) {
mLocationClient.requestLocationUpdates(REQUEST, locationListener);
}
};
OnConnectionFailedListener onConnectionFailedListener = new OnConnectionFailedListener() {
@Override
public void onConnectionFailed(ConnectionResult result) {
}
};
OnMyLocationChangeListener onMyLocationChangeListener = new OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(Location location) {
}
};
LocationListener locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
float diff = 0;
if (lastLocation != null) {
diff = location.distanceTo(lastLocation);
}
if ((lastLocation == null) || (diff > 5)) {
LatLng latLng = new LatLng(location.getLatitude(),
location.getLongitude());
CameraPosition cameraPosition = new CameraPosition(latLng, 14,
45, 0);
CameraUpdate cameraUpdate = CameraUpdateFactory
.newCameraPosition(cameraPosition);
mMap.animateCamera(cameraUpdate, 25, null);
mMap.getUiSettings().setZoomControlsEnabled(true);
mMap.getUiSettings().setZoomGesturesEnabled(true);
//new PlacesAPICall().execute();
lastLocation = location;
}
}
};
String urlString;
class PlacesAPICall extends AsyncTask<Void, Void, Void> {
JSONObject jObject;
@Override
protected void onPreExecute() {
super.onPreExecute();
showLoadingDialog();
}
@Override
protected Void doInBackground(Void... params) {
BufferedReader reader = null;
String key = "D###0545-58###39-6#####D-41####77-4#####8-###1C28-D524###7-#####4F5";
String category = "287";// For the nearest medical related facilities. It could be a pharmacy,clinic hospital etc.
if(isHospital == true){
// urlString = "http://api.wikimapia.org/?key="+key+"&function=place.getnearest&q=&lat="+lastLocation.getLatitude()+"&lon="+lastLocation.getLongitude()+"&format=json&pack=&language=en&page=1&count=100&category="+category+"&categories_or=&categories_and=&distance=";//Hospital
urlString = "http://api.wikimapia.org/?key="+key+"&function=place.search&q=&lat="+lastLocation.getLatitude()+"&lon="+lastLocation.getLongitude()+"&format=json&pack=&language=en&page=1&count=50&category=287&categories_or=&categories_and=&distance=";
}else if(isMetro == true){
urlString = "http://api.wikimapia.org/?key="+key+"&function=place.search&lat="+lastLocation.getLatitude()+"&lon="+lastLocation.getLongitude()+"&format=json&pack=&language=en&count=100&category="+44758;//Metro
}else if(isPolice == true){
urlString = "http://api.wikimapia.org/?key="+key+"&function=place.search&lat="+lastLocation.getLatitude()+"&lon="+lastLocation.getLongitude()+"&format=json&pack=&language=en&count=100&category="+670;// Police
}
if(connectionStatus){
try {
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(
conn.getOutputStream());
wr.flush();
reader = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
// Append server response in string
sb.append(line + "");
}
String content = sb.toString();
Logs.v(getLocalClassName(),
"Places API InBackgroung, Contect = " + content);
try {
jObject = new JSONObject(content);
} catch (Exception e) {
Logs.e("Exception", e.toString());
}
} catch (Exception ex) {
Logs.v(getLocalClassName(), "Places API InBackgroung, Error = "
+ ex.toString());
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
Bitmap bitmap = null;
String icon = "", latitude = "", longitude = "",distance = "",place = "";
if(connectionStatus==true){
try {
// JSONArray arrayOfPlaces = jObject.getJSONArray("results");
JSONArray arrayOfPlaces = jObject.getJSONArray("places");
for (int i = 0; i < arrayOfPlaces.length(); i++) {
JSONObject jPlace = arrayOfPlaces.getJSONObject(i);
if (!jPlace.isNull("title")) {
place = jPlace.getString("title");
}
if (!jPlace.isNull("urlhtml")) {
icon = jPlace.getString("urlhtml");
}
if (!jPlace.isNull("id")) {
distance = jPlace.getString("id");
}
if (!jPlace.isNull("distance")) {
distance = jPlace.getString("distance");
}
longitude = jPlace.getJSONObject("location").getString("lon");
latitude = jPlace.getJSONObject("location").getString("lat");
double lat = Double.parseDouble(latitude);
double lng = Double.parseDouble(longitude);
LatLng latLng = new LatLng(lat, lng);
//mMap.clear();
// It clears the whole map
markerOptions.position(latLng);
markerOptions.title(place);
markerOptions.icon(BitmapDescriptorFactory.fromResource(R.drawable.pin_x));
mMap.getUiSettings().setZoomControlsEnabled(true);
mMap.addMarker(markerOptions).setSnippet("Distance "+distance);
mMap.addMarker(markerOptions).showInfoWindow();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
dismissLoadingDialog();
}
dismissLoadingDialog();
}
}
}
@Override
public void onMapLongClick(LatLng arg0) {
// TODO Auto-generated method stub
}
}
答案 0 :(得分：1)
你应该调用mMap.clear（）;在这种方法中，所以当你调用它时，它将清除地图，然后重新分配标记。
private void setUpMapIfNeeded() {
if (mMap == null) {
mMap = ((SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map)).getMap();
mMap.clear();
mMap.setOnMapClickListener(MyLocationActivity.this);
if (mMap != null) {
mMap.setOnMapClickListener(MyLocationActivity.this);
mMap.setMyLocationEnabled(true);
mMap.setBuildingsEnabled(true);
mMap.setIndoorEnabled(true);
mMap.setMapType(mMap.MAP_TYPE_NORMAL);
mMap.setTrafficEnabled(true);
}
}
}
在您的点击监听器中，您应该使您的mMap等于null，这样它可以使您的上述条件成为真，并帮助您清除地图并重新分配标记。
ImageView imgPublicToilet = (ImageView) findViewById(R.id.imgPublicToilet);
imgPublicToilet.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mMap = null;
setUpMapIfNeeded();
}
});
答案 1 :(得分：0)
执行mMap.addMarker(markerOptions)后，您应该保存标记的引用，然后对标记执行.remove()操作。
所以，它应该看起来像......
private GoogleMap gMap;
private Marker myMarker;
....
....//where you add the marker
myMarker = gMap.addMarker(marker);
myMarker.showInfoWindow();
....
....//where you remove the marker
myMarker.remove();