假设我们在地图上有一个居中的标记，当我们用手指移动地图时，我们可以看到当您离开该区域时，该标记将不再显示。那么，尽管我们将地图移动到任何地方，我们如何制作一个始终保持在地图中心的标记呢？有一个名为 UBER 的应用程序，他们提供此功能，您无需拖放标记，只需移动地图，标记保持其位置。
这是一个屏幕截图：
如您所见，当我们移动地图时，绿色标记位于屏幕中央，它保持原位，但在用户停止移动地图时显示新位置。我们怎么能这样呢？
我有一个代码在您拖放标记时显示地址，如何再次显示地址但这次不是通过拖动，移动地图？希望你能理解任何想法都会很棒。
public class MainActivity extends AbstractMapActivity implements
OnNavigationListener, OnInfoWindowClickListener,
OnMarkerDragListener {
private static final String STATE_NAV="nav";
private static final int[] MAP_TYPE_NAMES= { R.string.normal,
R.string.hybrid, R.string.satellite, R.string.terrain };
private static final int[] MAP_TYPES= { GoogleMap.MAP_TYPE_NORMAL,
GoogleMap.MAP_TYPE_HYBRID, GoogleMap.MAP_TYPE_SATELLITE,
GoogleMap.MAP_TYPE_TERRAIN };
private GoogleMap map=null;
String filterAddress = "";
Marker marker;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (readyToGo()) {
setContentView(R.layout.activity_main);
SupportMapFragment mapFrag=
(SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
mapFrag.setRetainInstance(true);
initListNav();
map=mapFrag.getMap();
if (savedInstanceState == null) {
CameraUpdate center=
CameraUpdateFactory.newLatLng(new LatLng(
41.003739,
28.999572));
CameraUpdate zoom=CameraUpdateFactory.zoomTo(10);
map.moveCamera(center);
map.animateCamera(zoom);
addMarker(map, 41.003739, 28.999572, R.string.un, R.string.united_nations);
map.setInfoWindowAdapter(new PopupAdapter(getLayoutInflater()));
map.setOnInfoWindowClickListener(this);
map.setOnMarkerDragListener(this);
}
}
}
@Override
public boolean onNavigationItemSelected(int itemPosition, long itemId) {
map.setMapType(MAP_TYPES[itemPosition]);
return(true);
}
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putInt(STATE_NAV,
getSupportActionBar().getSelectedNavigationIndex());
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
getSupportActionBar().setSelectedNavigationItem(savedInstanceState.getInt(STATE_NAV));
}
@Override
public void onInfoWindowClick(Marker marker) {
Toast.makeText(this, marker.getTitle(), Toast.LENGTH_LONG).show();
}
@Override
public void onMarkerDragStart(Marker marker) {
LatLng position=marker.getPosition();
Log.d(getClass().getSimpleName(), String.format("Drag from %f:%f",
position.latitude,
position.longitude));
}
@Override
public void onMarkerDrag(Marker marker) {
LatLng position=marker.getPosition();
Log.d(getClass().getSimpleName(),
String.format("Dragging to %f:%f", position.latitude,
position.longitude));
}
@Override
public void onMarkerDragEnd(Marker marker) {
LatLng position=marker.getPosition();
String filterAddress = "";
Geocoder geoCoder = new Geocoder(
getBaseContext(), Locale.getDefault());
try {
List<Address> addresses = geoCoder.getFromLocation(
position.latitude,
position.longitude, 1);
if (addresses.size() > 0) {
for (int index = 0;
index < addresses.get(0).getMaxAddressLineIndex(); index++)
filterAddress += addresses.get(0).getAddressLine(index) + " ";
}
}catch (IOException ex) {
ex.printStackTrace();
}catch (Exception e2) {
// TODO: handle exception
e2.printStackTrace();
}
Log.d(getClass().getSimpleName(),
String.format("Dragging to %f:%f", position.latitude,
position.longitude));
TextView myTextView = (TextView) findViewById(R.id.test);
myTextView.setText("Address is: " + filterAddress);
}
private void initListNav() {
ArrayList<String> items=new ArrayList<String>();
ArrayAdapter<String> nav=null;
ActionBar bar=getSupportActionBar();
for (int type : MAP_TYPE_NAMES) {
items.add(getString(type));
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
nav=
new ArrayAdapter<String>(
bar.getThemedContext(),
android.R.layout.simple_spinner_item,
items);
}
else {
nav=
new ArrayAdapter<String>(
this,
android.R.layout.simple_spinner_item,
items);
}
nav.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
bar.setListNavigationCallbacks(nav, this);
}
private void addMarker(GoogleMap map, double lat, double lon,
int title, int snippet)
{
map.addMarker(new MarkerOptions().position(new LatLng(lat, lon))
.icon(BitmapDescriptorFactory.fromResource(R.drawable.pin))
.draggable(true));
}
}
这是xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/img_header" >
<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment" />
<TextView
android:id="@+id/test"
android:layout_width="match_parent"
android:layout_height="90dp"
android:layout_alignParentRight="true"
android:text="Address : "
android:textColor="#FF0000"
android:textSize="22sp" />
</RelativeLayout>