Question

在遇到一些解析问题inflating the XML之后，我决定采用一种程序化的解决方法。地图已正确添加到场景中，但我将其作为类成员缓存以供以后使用时出现问题。这是爆炸点的代码片段。

的活动：

public class MoogliActivity extends FragmentActivity {

public void onCreate(final Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  this.setContentView(R.layout.main);
  final SupportMapFragment supportMap = SupportMapFragment.newInstance();
  final FragmentTransaction fragmentTransaction = this.getSupportFragmentManager()
            .beginTransaction();
 fragmentTransaction.add(R.id.maplayout, supportMap);
 fragmentTransaction.commit();
 mGoogleMap = supportMap.getMap(); // mGoogleMap = null after this
 // mGoogleMap.setMyLocationEnabled(true); Obviously NullPointerException
}

}

main.xml中

<RelativeLayout
    android:id="@+id/maplayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_alignBottom="@+id/tracking"
    android:layout_below="@id/header" />

Answer 1

此代码：

mGoogleMap = supportMap.getMap();

应该在onCreate之后调用。试试onResume（），就像这样。

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

    // here it should work
    mGoogleMap = supportMap.getMap(); 

    // In case Google Play services has since become available.
    setUpMapIfNeeded();
}

以编程方式添加时检索SupportMapFragment的GoogleMap成员时出错

1 个答案: