从另一个活动返回后应用程序未恢复捆绑包

Question

我有一个使用谷歌地图的应用程序。我将 latLngBounds 保存到变量中，然后捆绑到以后检索它。我的问题是我想保存屏幕的当前位置，然后将相机移动到那个 LatLng。但是每次当我单击标记并启动另一个活动并返回时，屏幕都会以单击的标记为中心，但我想摆脱此功能并使屏幕返回到之前的位置。

编辑：问题是我的应用程序没有从包中恢复数据，我不知道为什么。以下是我保存和恢复状态的方法，但都不起作用：

@Override
protected void onCreate(Bundle bundle) {
    super.onCreate(bundle);
    //requestWindowFeature(Window.FEATURE_ACTION_BAR);
    setContentView(R.layout.activity_main);
    if (bundle!= null){
        lat = bundle.getDouble("lat1",0);
        lon = bundle.getDouble("lon1",0);
        ne3 = bundle.getDouble("lat2",-200);
        ne4 = bundle.getDouble("lon2",-200);
        Log.d("tag","bundle is not null");
    }
    setUpMapIfNeeded();
}
@Override
public void onPause() {
    super.onPause();
    manager.removeUpdates(this);
}

@Override
protected void onResume() {
    super.onResume();
    if (bundle!= null){
        lat = bundle.getDouble("lat1",0);
        lon = bundle.getDouble("lon1",0);
        ne3 = bundle.getDouble("lat2",-200);
        ne4 = bundle.getDouble("lon2",-200);
        Log.d("tag","bundle is not null");
    }
    setUpMapIfNeeded();
}
@Override
protected void onSaveInstanceState(Bundle bundle) {
    Log.e("tag","calling onSave");
    if(mMap!=null){
    LatLngBounds location3 = mMap.getProjection().getVisibleRegion().latLngBounds;
    double lat4 = location3.getCenter().latitude;
    double lon4 = location3.getCenter().longitude;
    double lat5 = location3.northeast.latitude;
    double lon5 = location3.northeast.longitude;
    bundle.putDouble("lat1", lat4);
    bundle.putDouble("lon1",lon4);
    bundle.putDouble("lat2",lat5);
    bundle.putDouble("lon2",lon5);
    }
    super.onSaveInstanceState(bundle);
}
@Override
public void onRestoreInstanceState(Bundle bundle) {
    super.onRestoreInstanceState(bundle);
    if (bundle!= null){
        lat = bundle.getDouble("lat1",0);
        lon = bundle.getDouble("lon1",0);
        ne3 = bundle.getDouble("lat2",-200);
        ne4 = bundle.getDouble("lon2",-200);
        Log.d("tag","bundle is not null");
    }
    setUpMapIfNeeded();
    // ... recover more data
}

问题似乎是从另一个活动返回时捆绑包以某种方式为空

Answer 1

问题是地图在启动 onSavedInstanceState() 之前自动居中，所以我保存了居中的数据，这就是它不起作用的原因。