Question

我有使用IndexedStack的BottomNavigationBar，以便在更改页面时不会重新加载我的googleMaps。在第一页中，我有一个按钮，在第二页中，我有googleMaps。当我按下按钮时，我希望页面更改为第二页，然后在其中调用函数。例如，缩放到新位置。

我正在使用范围模型来处理状态。

我已经找到了一种更改页面的方法，但是我不确定该如何使用GoogleMapsController。我将其提升为ScopedModel类，但现在在打开新路线并关闭它并尝试进行更改时遇到错误，请按一下按钮以转到地图上的某个位置：

I/flutter ( 8784): ══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
I/flutter ( 8784): The following NoSuchMethodError was thrown while handling a gesture:
I/flutter ( 8784): The method 'animateCamera' was called on null.
I/flutter ( 8784): Receiver: null
I/flutter ( 8784): Tried calling: animateCamera(Instance of 'CameraUpdate')
I/flutter ( 8784): 
I/flutter ( 8784): When the exception was thrown, this was the stack:
I/flutter ( 8784): #0      Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
I/flutter ( 8784): #1      AppStateModel.goToMapLocation 
package:restapoints/state/app_state.dart:57
I/flutter ( 8784): #2      RestaurantInfoPageState.build.<anonymous closure>.<anonymous closure> 
package:restapoints/pages/restaurant_page.dart:56
I/flutter ( 8784): #3      _InkResponseState._handleTap 
package:flutter/…/material/ink_well.dart:507
I/flutter ( 8784): #4      _InkResponseState.build.<anonymous closure> 
package:flutter/…/material/ink_well.dart:562
I/flutter ( 8784): #5      GestureRecognizer.invokeCallback 
package:flutter/…/gestures/recognizer.dart:102
I/flutter ( 8784): #6      TapGestureRecognizer._checkUp 
package:flutter/…/gestures/tap.dart:242
I/flutter ( 8784): #7      TapGestureRecognizer.acceptGesture 
package:flutter/…/gestures/tap.dart:204
I/flutter ( 8784): #8      GestureArenaManager.sweep 
package:flutter/…/gestures/arena.dart:156
I/flutter ( 8784): #9      _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent 
package:flutter/…/gestures/binding.dart:184
I/flutter ( 8784): #10     _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent 
package:flutter/…/gestures/binding.dart:158
I/flutter ( 8784): #11     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent 
package:flutter/…/gestures/binding.dart:138
I/flutter ( 8784): #12     _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue 
package:flutter/…/gestures/binding.dart:101
I/flutter ( 8784): #13     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket 
package:flutter/…/gestures/binding.dart:85
I/flutter ( 8784): #14     _invoke1 (dart:ui/hooks.dart:168:13)
I/flutter ( 8784): #15     _dispatchPointerDataPacket (dart:ui/hooks.dart:122:5)
I/flutter ( 8784): 
I/flutter ( 8784): Handler: onTap
I/flutter ( 8784): Recognizer:
I/flutter ( 8784):   TapGestureRecognizer#5de3a(debugOwner: GestureDetector, state: ready, won arena, finalPosition:
I/flutter ( 8784):   Offset(320.8, 298.5), sent tap down)
I/flutter ( 8784): ════════════════════════════════════════════════════════════════════════════════════════════════════

谢谢！

Answer 1

read about initState()

这是创建窗口小部件时调用的第一个方法，它必须为StatefullWidget

  @override
  void initState() {
    // You can call your zooom to new location function here
    super.initState();
  }

Answer 2

通过将ScopedModel移到小部件树顶部解决了此错误：

  AppStateModel model = AppStateModel();
      runApp(
    ScopedModel<AppStateModel>(
      model: model,
      child: MaterialApp(
        home: HomeWidget(),
      ),
    ),
  );

因此，对于任何在tabNav中重新加载googlemaps遇到麻烦的人，请使用索引堆栈并将所有页面包装到Navigator中。然后将GooglemapsController提升到ScopedModel并将ScopedModel（或任何其他状态管理模型）放置到应用程序的根目录。

打开新路线时出现Flutter Googlemaps错误

2 个答案: