Flutter疑难杂症系列二：context中报错 To saf

页面有Dialog，如下：

  Future<dynamic> showCompleteMoveDialog(BuildContext context) {
    return showDialog(
        context: context,
        builder: (context) {
          return CommonDialog('确认*****？', ' ',
              cancelTxt: '取消', confirmClick: () => _toDetailPage(context, _locationItem?.billNo));
        });
  }

  _toDetailPage(BuildContext context, String? billNo) {
    Navigator.push(
      context,
      MaterialPageRoute(builder: (con) {
        return MoveStockDetailPage(
          params: {'billNo': billNo},
        );
      }),
    );
  }

弹出dialog后，点击确定，跳转页面时报以下错误：

E/flutter (21072): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: Looking up a deactivated widget's ancestor is unsafe.
E/flutter (21072): At this point the state of the widget's element tree is no longer stable.
E/flutter (21072): To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.
E/flutter (21072): #0      Element._debugCheckStateIsActiveForAncestorLookup.<anonymous closure> (package:flutter/src/widgets/framework.dart:4032:9)
E/flutter (21072): #1      Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:4046:6)
E/flutter (21072): #2      Element.findAncestorStateOfType (package:flutter/src/widgets/framework.dart:4093:12)
E/flutter (21072): #3      Navigator.of (package:flutter/src/widgets/navigator.dart:2736:40)
E/flutter (21072): #4      Navigator.push (package:flutter/src/widgets/navigator.dart:2137:22)
E/flutter (21072): #5      _MoveStockCompletionPageState._toDetailPage (package:flutter_xms/wms/inside/movestock/move_stock_completion_page.dart:312:15)
E/flutter (21072): #6      _MoveStockCompletionPageState._completeMoving (package:flutter_xms/wms/inside/movestock/move_stock_completion_page.dart:303:7)

翻译过来是：

要在dispose（）方法中安全地引用小部件的祖先，请通过在小部件的didChangeDependencies（）方法中调用inheritFromWidgetOfExactType（）来保存对祖先的引用。

意思就是context引用的组件已经被销毁，context不可用。

所以最终原因是context引用错误；
我这里是dialog点击了确定后，dialog已销毁，所以报引用错误；这里改成页面的context即可。