Question

我是Flutter的新手，我正在尝试开发一个应用程序，因此nom在如何显示经过过滤的ListView.builder方面遇到了麻烦

这是小部件代码：

@override
Widget build(BuildContext context) {

print('Favorites');
return Container(
  color: AppColors.hexToColor('F0F4F5'),
  alignment: Alignment.topCenter,
  child: Column(
    children: <Widget>[
      HeaderCity(),
      Expanded(
        child: Container(
          padding: EdgeInsets.only(left: 16.0, right: 16.0),
          child: Container(
            child: StreamBuilder<CoworkingState>(
                stream: Provider.coworkingBlocOf(context).streamCoworkingState,
                initialData: CoworkingState(),
                builder: (BuildContext context, AsyncSnapshot<CoworkingState> snapshot) {
                  return (snapshot.data.isLoading)
                      ? CustomCircularLoader()                          
                      : ListView.builder(
                          padding: EdgeInsets.all(0.0),
                          itemBuilder: (BuildContext context, int index) {
                            if (snapshot.data.coworking.any((isFavorite) => true)){
                              return CoworkingCellDetail(
                                onTap: () {
                                  Provider.coworkingBlocOf(context)
                                      .selectCoworking(coworking: snapshot.data.coworking[index]);
                                  Future.delayed(Duration.zero, () {
                                    changeRoute(context, Routes.coworkDetail, false);
                                  });
                                },
                                isFavorite: snapshot.data.coworking[index].isFavorite,
                                name: snapshot.data.coworking[index].name,
                                adress: snapshot.data.coworking[index].address,
                                phone: snapshot.data.coworking[index].phone,
                                hour: snapshot.data.coworking[index].openingHours,
                                urlImages: snapshot.data.coworking[index].imagesUrl,
                                onFavoriteTap: () {
                                  Provider.coworkingBlocOf(context).removeFavorite(snapshot.data.coworking[index].id);
                                }
                              );
                            } return null; 
                          },
                          itemCount: snapshot.data.coworking.length,
                        );
                }),
          ),
        ),
      ),
    ],
  ),
);

}

所以现在这将返回完整列表，我只想显示带有isFavorite = true的项目

Answer 1

如果条件无法正常工作，您就不会这样做。

对于每种情况，您都返回true，这就是为什么添加所有项目的原因。

尝试以下一项：

...
if (snapshot.data.coworking.any((isFavorite) => isFavorite)){ //here it return true if isFavorite is true and if isFavorite is false then it will return false.
....

Answer 2

假设您的isFavorite数据类型为bool，如果它是字符串，则将以下if语句更改为此快照。data.coworking[index] .isFavorite.toString（）==“ true”

if(snapshot.data.coworking[index].isFavorite){
       return CoworkingCellDetail(
                                onTap: () {
                                  Provider.coworkingBlocOf(context)
                                      .selectCoworking(coworking: snapshot.data.coworking[index]);
                                  Future.delayed(Duration.zero, () {
                                    changeRoute(context, Routes.coworkDetail, false);
                                  });
                                },
                                isFavorite: snapshot.data.coworking[index].isFavorite,
                                name: snapshot.data.coworking[index].name,
                                adress: snapshot.data.coworking[index].address,
                                phone: snapshot.data.coworking[index].phone,
                                hour: snapshot.data.coworking[index].openingHours,
                                urlImages: snapshot.data.coworking[index].imagesUrl,
                                onFavoriteTap: () {
                                  Provider.coworkingBlocOf(context).removeFavorite(snapshot.data.coworking[index].id);
                                }
                              );
    }

尝试在Flutter中过滤StreamBuilder中的ListView.builder

2 个答案: