谷歌地图无法加载 - Android

Question

我得到的当前错误是：使用 newLatLngBounds(LatLngBounds, int) 时出错：地图大小不能为 0。很可能，地图视图的布局尚未发生。要么等到布局发生，要么使用 newLatLngBounds(LatLngBounds, int, int, int) 来指定地图的尺寸​​。

我假设我收到此错误是因为尚未加载布局，如何在我的代码中纠正此问题？

    import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.LatLngBounds;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.

    private LatLngBounds AUSTRALIA = new LatLngBounds(
            new LatLng(-44, 113), new LatLng(-10, 154));


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        setUpMapIfNeeded();


    }



    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    /**
     * Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
     * installed) and the map has not already been instantiated.. This will ensure that we only ever
     * call {@link #setUpMap()} once when {@link #mMap} is not null.
     * <p/>
     * If it isn't installed {@link SupportMapFragment} (and
     * {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
     * install/update the Google Play services APK on their device.
     * <p/>
     * A user can return to this FragmentActivity after following the prompt and correctly
     * installing/updating/enabling the Google Play services. Since the FragmentActivity may not
     * have been completely destroyed during this process (it is likely that it would only be
     * stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
     * method in {@link #onResume()} to guarantee that it will be called.
     */
    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();
            }
        }
    }




    /**
     * This is where we can add markers or lines, add listeners or move the camera. In this case, we
     * just add a marker near Africa.
     * <p/>
     * This should only be called once and when we are sure that {@link #mMap} is not null.
     */
    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
        mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(AUSTRALIA, 0));
    }

}

SetUpMap(); 方法中的行：mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(AUSTRALIA, 0));。顺便说一句，导致这个问题，当我尝试使用谷歌的 API V2 文档时，我是否需要在地图加载后在谷歌地图上使用回调，或者在特定时间段后使用单独的方法来初始化？

Answer 1

您的地图似乎还没有准备好。
您可以使用 MapLoadedCallBack；

map.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
  @Override
  public void onMapLoaded() {
      map.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 30));
  }
});

你也可以先看看这个。

 map.setOnCameraChangeListener(new GoogleMap.OnCameraChangeListener() {
        @Override
        public void onCameraChange(CameraPosition arg0) {
        map.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 30));
  }
});