android - 在 getMapAsync() 中调用 GoogleMap.getProjection() 时 IllegalArgumentException left == right

Question

更新到最新的支持库(版本 24.2.0)并将 compileSdkVersion 设置为 24 后，我开始在旋转后调用 GoogleMap.getProjection() 时看到 IllegalArgumentException left == right。

map 的初始渲染有效，当旋转回原始方向时，不会抛出异常。它只是从原来的方向到另一个方向(每次旋转从原来的方向改变到新的方向时都会发生异常)

使用相同代码返回支持库的 23.4.0 版不会出现此行为。所以，我不确定最新的支持库是否存在问题(这应该与 GoogleMap 无关)，或者最新版本只是在我的代码中暴露了一个错误。

两个版本都使用相同的 Google Play 服务 (9.4.0)。

我读过关于应该在 onMapLoadedCallback 内部访问投影的建议，但我的假设是在 getMapAsync 方法内调用 GoogleMap 实例上的方法会很好，因为这应该可以保证 map 可以使用。

堆栈跟踪:

java.lang.IllegalArgumentException: left == right
        at android.opengl.Matrix.frustumM(Matrix.java:327)
        at com.google.maps.api.android.lib6.gmm6.n.b.b.j(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.b.b.l(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.b.b.b(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.b.b.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.b.b.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.c.v.a(Unknown Source)
        at com.google.maps.api.android.lib6.d.aw.a(Unknown Source)
        at com.google.android.gms.maps.internal.cb.onTransact(SourceFile:82)
        at android.os.Binder.transact(Binder.java:387)
        at com.google.android.gms.maps.internal.IProjectionDelegate$zza$zza.getVisibleRegion(Unknown Source)
        at com.google.android.gms.maps.Projection.getVisibleRegion(Unknown Source)
        at com.google.maps.android.clustering.view.DefaultClusterRenderer$RenderTask.run(DefaultClusterRenderer.java:363)
        at java.lang.Thread.run(Thread.java:818)

相关 fragment 如下:

 public class MyMapFragment extends Fragment
 {
    @Nullable
    private SupportMapFragment m_mapFragment;

    // fragment setup code removed for this snippet

    /** Assign the map fragment variable on resume. This is necessary for orientation change events */
    @Override
    public void onResume ()
    {
       super.onResume();

       // We can get here in (at least) 3 different ways:
       // 1. The first time this fragment is created.
       //       In this case, we will not have a local reference to a map fragment and will will add
       //       it if we are the currently displaying fragment.
       // 2. After rotation
       //       Because the actual map fragment is maintained by our activity, the map fragment will
       //       have been recreated and our reference to it will no longer be valid.
       // 3. After a pause event (such as the device going into power saving mode).
       //       We should still have a reference to the current map fragment and it should be
       //       valid. We can test that by checking if the map fragment is attached. This is done
       //       in the setMapFragment() method.
       //
       final AlbumActivity activity = (AlbumActivity)getActivity();

       Fragment currentFragment = activity.getCurrentItemFragment() ;

       if( m_mapFragment == null && this == currentFragment )
       {
          setMapFragment( activity.getMapFragment() );
       }
       else if ( m_mapFragment != null )
       {
          setMapFragment( activity.getMapFragment() );
       }
       else
       {
          // just update the map 
          updateMap() ;
       }
    }

    private void updateMap()
    {
       if ( m_mapFragment == null )
       {
           return;
       }

       m_mapFragment.getMapAsync( new OnMapReadyCallback()
       {
           @Override
           public void onMapReady( GoogleMap googleMap )
           {
               try
               {
                  googleMap.clear();

                  // Exception thrown here!
                  final Projection projection = googleMap.getProjection() ;
                  final VisibleRegion visibleRegion = projection.getVisibleRegion() ;

                  LatLngBounds mapBounds = visibleRegion.latLngBounds;

                  // more done on map here (markers, etc.)
                }
                catch ( IllegalStateException e )
                {
                  // basically, wait 100 ms and try again. However,
                  // the exception seems to not go away until rotation goes back to original orientation
                  configureAfterDelay();
                }
           }
       } ) ;
    }

    public void setMapFragment ( @Nullable SupportMapFragment mapFragment )
   {
      // The working assumption is that our map fragment, if already added, is added to
      // our current fragment.
      if ( mapFragment != null && mapFragment.isAdded() == false )
      {
         final FragmentManager fragmentManager = getChildFragmentManager();

         // Add the map view to the current view
         fragmentManager.beginTransaction()
            .add( R.id.mapview_container, mapFragment, MAP_FRAGMENT_TAG )
        .commit();

         fragmentManager.executePendingTransactions();
      }

      m_mapFragment = mapFragment;

      updateMap( );
   }

我在其他地方看到了以下问题，但没有找到解决方案:

https://code.google.com/p/gmaps-api-issues/issues/detail?id=8724

Answer 1

我知道已经很晚了，但我今天刚遇到这个问题...问题是本地图的大小为 0 并且您尝试访问 map.Projection.VisibleRegion 时。错误消息的字面意思是投影的左侧与投影的右侧相同，如果 map View 的宽度为 0，就会发生这种情况。要绕过它，请确保您只访问 map 投影的 VisibleRegion当 mapView 的宽度 > 0 时。

var extent = mapView.Width > 0 ? map.Projection.VisibleRegion.LatLngBounds : null;