如何从摩尔中删除所有内容？

Question

我试图在注销时删除所有内容。

onPressed: () {
       _categoryBloc.deleteEntry();
 }

但是错误来了

未处理的异常：NoSuchMethodError：在 null 上调用了方法“deleteEntry”。E/flutter（9255）：接收器：null E/flutter（9255）：尝试调用：deleteEntry()

初始集团

 CategoryBloc _categoryBloc;

MyBloc 类

class CategoryBloc {
...
      void deleteEntry() {
        _categoryRepository.deleteCategory();
      }
...
}

我的回购课程

deleteCategory() async {
    try{
      await _categoryDao.deleteEntry();
    }catch (e){
      print('Caught in delete ${e.body}');
      rethrow;
    }
  }

道课

  Future deleteEntry() {
    return delete(categories).delete(Categorie());
  }

数据类

class Categorie extends DataClass implements Insertable<Categorie> {
  final String id;
  final bool isActive;
  final String categoryName;
  final int displayOrder;
  Categorie(
      {@required this.id,
      @required this.isActive,
      @required this.categoryName,
      @required this.displayOrder});
  factory Categorie.fromData(Map<String, dynamic> data, GeneratedDatabase db,
.....

Answer 1

onPressed像这样改变了方法

ProxyProvider<CategoriesRepository,CategoryBloc>(
          builder: (context, categoryRepo, categoryBloc)=>
              CategoryBloc(categoryRepository: categoryRepo),
          dispose: (context, categoryBloc)=> categoryBloc.dispose(),
          ).didChangeDependencies(context, _categoryBloc).deleteEntry();

并且如果你想删除所有你需要检查的查询，如下所示：

  deleteEntry() {
    try{
      return delete(subCategories).go();//like this
    }catch (e){
      print("error is $e");
    }
  }