如何在 Google Map API v2 中的 MapFragment 上显示多个标记? [英] How to show multiple markers on MapFragment in Google Map API v2?
问题描述
我在我的应用程序中使用 Google Map API v2 来显示地图.
I am using Google Map API v2 in my application to show Maps.
我已按照所有步骤操作，即在我的应用程序中启用 Google 地图.
I have followed all the steps, that is to be followed to enable Google Map in my application.
public class PinLocationOnMapView extends FragmentActivity {
private double mLatitude = 0.0, mLongitude = 0.0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SupportMapFragment fragment = SupportMapFragment.newInstance();
getSupportFragmentManager().beginTransaction()
.add(android.R.id.content, fragment).commit();
}
}
如果我使用此代码，它会显示我的地图，但如果我提供我的纬度/经度值，地图图块不会加载，我只能看到白色图块.
If I use this code, it shows me map, but if I provide my latitude/longitude values, map tiles does not load, and I see only white tiles.
下面是上面类的onCreate()编写的代码:
Following is the code written in onCreate() of above class:
if (getIntent().getExtras() != null) {
final Bundle bundle = getIntent().getBundleExtra("LOCATION");
mLatitude = bundle.getDouble("LATITUDE");
mLongitude = bundle.getDouble("LONGITUDE");
} else {
finish();
}
GoogleMapOptions options = new GoogleMapOptions();
LatLng latLng = new LatLng(mLatitude, mLongitude);
CameraPosition cameraPosition;// = new CameraPosition(latLng, 0, 0, 0);
cameraPosition = CameraPosition.fromLatLngZoom(latLng, (float) 14.0);
options.mapType(GoogleMap.MAP_TYPE_SATELLITE).camera(cameraPosition)
.zoomControlsEnabled(true).zoomGesturesEnabled(true);
SupportMapFragment fragment = SupportMapFragment.newInstance(options);
getSupportFragmentManager().beginTransaction()
.add(android.R.id.content, fragment).commit();
另外，我有一个经纬度值列表.我想在 MapFragment 上显示它们，如何在 MapFragment 上显示多个标记?
Also, I have a list of lat/long values. I want to show them on MapFragment, how to show multiple markers on MapFragment?
我尝试了 MapView 和 ItemizedOverlay，但它对我不起作用.我相信我已经正确创建了 SHA1 密钥来获取 API 密钥，因为如果那是错误的，我将看不到使用 MapFragment 作为的地图好吧，但如果我不传递 lat/log 值，我可以看到.
I tried with MapView and ItemizedOverlay, but it didn't work for me. I believe I have correctly created the SHA1 key to get the API key, because if that was wrong, I could not see map using MapFragment as well, but I can see that if I don't pass the lat/log value.
推荐答案
我这样做是为了在地图上用不同颜色的标记显示汽车位置:
I do it like this to show car positions on the map with markers of different colors:
private void addMarkersToMap() {
mMap.clear();
for (int i = 0; i < Cars.size(); i++) {
LatLng ll = new LatLng(Cars.get(i).getPos().getLat(), Cars.get(i).getPos().getLon());
BitmapDescriptor bitmapMarker;
switch (Cars.get(i).getState()) {
case 0:
bitmapMarker = BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED);
Log.i(TAG, "RED");
break;
case 1:
bitmapMarker = BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN);
Log.i(TAG, "GREEN");
break;
case 2:
bitmapMarker = BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_ORANGE);
Log.i(TAG, "ORANGE");
break;
default:
bitmapMarker = BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED);
Log.i(TAG, "DEFAULT");
break;
}
mMarkers.add(mMap.addMarker(new MarkerOptions().position(ll).title(Cars.get(i).getName())
.snippet(getStateString(Cars.get(i).getState())).icon(bitmapMarker)));
Log.i(TAG,"Car number "+i+" was added " +mMarkers.get(mMarkers.size()-1).getId());
}
}
}
Cars 是自定义对象的 ArrayList，而 mMarkers 是标记的 ArrayList.
Cars is an ArrayList of custom objects and mMarkers is an ArrayList of markers.
注意:您可以像这样在片段中显示地图:
Note : You can show map in fragment like this:
private GoogleMap mMap;
....
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the
// map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
setUpMap();
}
}
}
private void setUpMap() {
// Hide the zoom controls as the button panel will cover it.
mMap.getUiSettings().setZoomControlsEnabled(false);
// Add lots of markers to the map.
addMarkersToMap();
// Setting an info window adapter allows us to change the both the
// contents and look of the
// info window.
mMap.setInfoWindowAdapter(new CustomInfoWindowAdapter());
// Set listeners for marker events. See the bottom of this class for
// their behavior.
mMap.setOnMarkerClickListener(this);
mMap.setOnInfoWindowClickListener(this);
mMap.setOnMarkerDragListener(this);
// Pan to see all markers in view.
// Cannot zoom to bounds until the map has a size.
final View mapView = getSupportFragmentManager().findFragmentById(R.id.map).getView();
if (mapView.getViewTreeObserver().isAlive()) {
mapView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@SuppressLint("NewApi")
// We check which build version we are using.
@Override
public void onGlobalLayout() {
LatLngBounds.Builder bld = new LatLngBounds.Builder();
for (int i = 0; i < mAvailableCars.size(); i++) {
LatLng ll = new LatLng(Cars.get(i).getPos().getLat(), Cars.get(i).getPos().getLon());
bld.include(ll);
}
LatLngBounds bounds = bld.build();
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 70));
mapView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
});
}
}
然后在 onCreate()
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