Android GMaps v2-获取地图中心位置以及地图的高度和宽度

Question

I'm trying to get the latitude and longitude of the center of the map in the Google Maps V2 API & get the width and length of the map.

Here is my old code(from GMaps v1 that I started to modify):

import com.google.android.gms.maps.GoogleMap;

private GoogleMap mGoogleMapView;

public LatLng getMapCenter()
{
  if( mGoogleMapView != null )
  {
     return mGoogleMapView.getMapCenter();
  }
  /*if( mOpenStreetMapView != null )
  {
     return convertOSMGeoPoint( mOpenStreetMapView.getMapCenter() );
  }*/
  return null;
}

public int getHeight()
{
  if( mGoogleMapView != null )
  {
     return mGoogleMapView.getHeight();
  }      
  /*if( mOpenStreetMapView != null )
  {
     return mOpenStreetMapView.getHeight();
  }*/
  return 0;
}

public int getWidth()
{
  if( mGoogleMapView != null )
  {
     return mGoogleMapView.getWidth();
  }
  /*else if( mOpenStreetMapView != null )
  {
     return mOpenStreetMapView.getWidth();
  }*/
  return 0;
} 

How can I perform the same functionality that mapView.getMapCenter(), mapView.getHeight(), and mapView.getWidth() using the Android GMaps V2 API?

Answer 1

Getting the center:

GoogleMap map;
LatLng center = map.getCameraPosition().target;

Getting the width and height:

If you're adding the MapFragment to your Activity using a FragmentTransaction , you have to provide some ViewGroup to put the fragment into. Something like a LinearLayout or such. Calling getWidth() and getHeight() on such ViewGroup should get you what you want.

Hope it helps. If you need an example, let me know.

EDIT - adding an example:

Take a look at the Google Maps Android API v2 , especially at the section named: Add a Fragment .

Under the part that starts with You can also add a MapFragment to an Activity in code , there is an example. In that example, R.id.my_container is exactly the ViewGroup I wrote about above. Somewhere in the XML layout of your Activity , there is something like this:

<LinearLayout
    android:id="@+id/my_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

What the FragmentTransaction does is that it takes a MapFragment and puts it as a child of this LinearLayout . The only child. Therefore the map has the same width and height as the LinearLayout .

Then you can easily get what you need in your Activity like this.

LinearLayout myContainer = (LinearLayout) findViewById(R.id.my_container);
int mapHeight = myContainer.getHeight();
int mapWidth = myContainer.getWidth();

I hope it's understandable.