如何在颤振中更新 GridView.builder 中的 Widget

Question

我想知道如何在 GridView.builder 中更新 Widget。 我在 GestureDetector 的 onTap 调用时使用了 setState()，但 Gridview.Builder 项目中的小部件没有改变。

这是改变状态的函数

Widget todayProductCard(String url, String name, String price, String mall,
  String discount, String imageURL, String like) {
bool _isSelected = false;
if (name.length >= 15) {
  name = name.substring(0, 15) + "...";
}
return GestureDetector(
  onTap: () {
    setState(() {
      _isSelected = !_isSelected;
      print(_isSelected.toString() + " " + name);
    });
  },
  child: Column(
    children: [
      ClipRRect(
        borderRadius: BorderRadius.circular(10),
        child: Stack(
          children: [
            Image.network(
              imageURL,
              width: MediaQuery.of(context).size.width / 2.2,
              height: MediaQuery.of(context).size.height / 4.5,
              fit: BoxFit.cover,
            ),
            Visibility(
              visible: _isSelected,

这是 build()（_productWidgetList 是上面的函数列表）

@override
Widget build(BuildContext context) {
 print("qkwueiuqoieuqoieuoiqueoique");
 return Scaffold(
   appBar: AppBar(
     actions: [
       Padding(
         padding: EdgeInsets.symmetric(
           horizontal: MediaQuery.of(context).size.width / 30,
         ),
         child: Icon(Icons.more_horiz),
       )
     ],
     // title: Text(widget.closetName),
     title: Text(toggle.toString()),
     centerTitle: true,
     brightness: Brightness.light,
   ),
   body: FutureBuilder(
       future: productList(widget.userID, widget.closetName),
       builder: (BuildContext context,
           AsyncSnapshot<List<ProductModel>> snapshot) {
         if (snapshot.hasData) {
           return GridView.builder(
             padding: EdgeInsets.fromLTRB(
               12,
               0,
               12,
               0,
             ),
             shrinkWrap: true,
             itemCount: snapshot.data.length,
             gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
               childAspectRatio: 0.7,
               crossAxisCount: 2,
               crossAxisSpacing: 8,
               mainAxisSpacing: 10,
             ),
             itemBuilder: (context, index) {
               return _productWidgetList[index];
             },
           );
         } else {
           return Container();
         }
       }),
 );
}
}

这是完整的代码

class FavoriteEditScreen extends StatefulWidget {
  const FavoriteEditScreen({Key key, this.userID, this.closetName})
      : super(key: key);

  final String userID;
  final String closetName;

  @override
  _FavoriteEditScreenState createState() => _FavoriteEditScreenState();
}

class _FavoriteEditScreenState extends State<FavoriteEditScreen> {
  ProductComponent productComponent = new ProductComponent();
  bool futureSemaphore = true;
  int httpPageNum = 1;
  String appbarString = "appbarString";

  List<Widget> _productWidgetList = [];

  Future<List<ProductModel>> productList(
      String userID, String closetName) async {
    Map body = {
      "abc": userID,
      "abc": closetName,
    };

    final response = await http.post(
      Uri.http("abcd.com".toString(), '/link'),
      body: body,
      headers: {
        "Accept": "application/json",
        'Content-Type': "application/x-www-form-urlencoded"
      },
    );

    final decodeData = utf8.decode(response.bodyBytes);
    var jsonArray = jsonDecode(decodeData) as List;
    List<ProductModel> products =
        await jsonArray.map((e) => ProductModel.fromJSON(e)).toList();
    print(products[0].title);
    return products;
  }

  @override
  void initState() {
    productList(widget.userID, widget.closetName).then((value) {
      generateProductList(value);
      return;
    });
    super.initState();
  }

  Widget todayProductCard(String url, String name, String price, String mall,
      String discount, String imageURL, String like) {
    bool _isSelected = false;
    if (name.length >= 15) {
      name = name.substring(0, 15) + "...";
    }
    return GestureDetector(
      onTap: () {
        setState(() {
          _isSelected = !_isSelected;
          print(_isSelected.toString() + " " + name);
        });
      },
      child: Column(
        children: [
          ClipRRect(
            borderRadius: BorderRadius.circular(10),
            child: Stack(
              children: [
                Image.network(
                  imageURL,
                  width: MediaQuery.of(context).size.width / 2.2,
                  height: MediaQuery.of(context).size.height / 4.5,
                  fit: BoxFit.cover,
                ),
                Visibility(
                  visible: _isSelected,
                  child: Opacity(
                    opacity: 0.4,
                    child: Container(
                      decoration: BoxDecoration(
                        color: Colors.lightGreen,
                        border: Border.all(
                          color: Colors.green[900],
                          width: 3,
                        ),
                        borderRadius: BorderRadius.circular(10),
                      ),
                      width: MediaQuery.of(context).size.width / 2.2,
                      height: MediaQuery.of(context).size.height / 4.5,
                    ),
                  ),
                ),
              ],
            ),
          ),
          Container(
            width: MediaQuery.of(context).size.width / 2.2,
            child: Padding(
              padding: EdgeInsets.symmetric(
                horizontal: MediaQuery.of(context).size.width / 70,
              ),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.start,
                children: [
                  Container(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        SizedBox(
                          height: MediaQuery.of(context).size.height / 200,
                        ),
                        Text(
                          // "$mall",
                          _isSelected.toString(),
                          style: TextStyle(
                            fontWeight: FontWeight.w700,
                            color: Colors.grey[700],
                            fontSize: MediaQuery.of(context).size.width / 38,
                          ),
                        ),
                        Text(
                          "$name",
                          style: TextStyle(
                            color: Colors.grey[700],
                            fontSize: MediaQuery.of(context).size.width / 35,
                          ),
                        ),
                        SizedBox(
                          height: MediaQuery.of(context).size.height / 200,
                        ),
                        Row(
                          children: [
                            Text(
                              (discount == "") ? "" : "$discount ",
                              style: TextStyle(
                                fontWeight: FontWeight.w900,
                                color: Colors.red,
                                fontSize:
                                    MediaQuery.of(context).size.width / 30,
                              ),
                            ),
                            Text(
                              "$price",
                              style: TextStyle(
                                fontWeight: FontWeight.w900,
                                fontSize:
                                    MediaQuery.of(context).size.width / 30,
                              ),
                            ),
                          ],
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  generateProductList(List<ProductModel> productList) {
    setState(() {
      _productWidgetList.addAll(
        List.generate(
          productList.length,
          (index) {
            return todayProductCard(
              productList[index].url,
              productList[index].title,
              productList[index].price,
              productList[index].mallName,
              productList[index].discount,
              productList[index].image,
              productList[index].likeBool,
            );
          },
        ),
      );
    });
  }

  bool toggle = false;

  @override
  Widget build(BuildContext context) {
    print("qkwueiuqoieuqoieuoiqueoique");
    return Scaffold(
      appBar: AppBar(
        actions: [
          Padding(
            padding: EdgeInsets.symmetric(
              horizontal: MediaQuery.of(context).size.width / 30,
            ),
            child: Icon(Icons.more_horiz),
          )
        ],
        // title: Text(widget.closetName),
        title: Text(toggle.toString()),
        centerTitle: true,
        brightness: Brightness.light,
      ),
      body: FutureBuilder(
          future: productList(widget.userID, widget.closetName),
          builder: (BuildContext context,
              AsyncSnapshot<List<ProductModel>> snapshot) {
            if (snapshot.hasData) {
              return GridView.builder(
                padding: EdgeInsets.fromLTRB(
                  12,
                  0,
                  12,
                  0,
                ),
                shrinkWrap: true,
                itemCount: snapshot.data.length,
                gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                  childAspectRatio: 0.7,
                  crossAxisCount: 2,
                  crossAxisSpacing: 8,
                  mainAxisSpacing: 10,
                ),
                itemBuilder: (context, index) {
                  return _productWidgetList[index];
                },
              );
            } else {
              return Container();
            }
          }),
    );
  }
}