未处理的异常:在_ScreenState.initState()完成之前调用了InheritFromFromWidgetOfExactType(_LocalizationsScope)或herineFromElement().

问题描述

我正在调用初始方法以使用initState从API加载数据.但这导致我出错.这是错误:

I am calling initial method to load data from API using initState. But it is resulting me an error. Here is error:

Unhandled Exception: inheritFromWidgetOfExactType(_LocalizationsScope) or inheritFromElement() was called before _ScreenState.initState() completed.
When an inherited widget changes, for example if the value of Theme.of() changes, its dependent widgets are rebuilt. If the dependent widget's reference to the inherited widget is in a constructor or an initState() method, then the rebuilt dependent widget will not reflect the changes in the inherited widget.

我的代码是:

@override
  void initState() {
    super.initState();

    this._getCategories();
  }

  void _getCategories() async {
    AppRoutes.showLoader(context);
    Map<String, dynamic> data = await apiPostCall(
      apiName: API.addUser,
      context: context,
      parameterData: null,
      showAlert: false,
    );
    if(data.isNotEmpty){
      AppRoutes.dismissLoader(context);
      print(data);

    }else {
      AppRoutes.dismissLoader(context);
    }
   }

推荐答案

您需要在 initState 完成后调用 _getCategories .

@override
void initState() {
   super.initState();

   Future.delayed(Duration.zero, () {
      this._getCategories();
   });

   // Could do this in one line: Future.delayed(Duration.zero, this._getCategories);
}

此外，您可以使用 addPostFrameCallback 就像在另一个答案中显示的一样.

Also, you could do this on a different way, using addPostFrameCallback like showed in another answers.

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