我正在尝试在列表视图中显示我的 JSON 响应。 颤振/飞镖

Question

This is the code to obtain the response and store it in a cache :

onPressed: () async{

                    var newMessage = await (ReadCache.getString(key: 'cache1'));

                      var response = await http.get(
                        Uri.parse(
                            'http://192.168.1.8:8080/HongLeong/MENU_REQUEST.do?_dc=1657717579436&table_id=25018&fk_table_id=25004&id_MenuAction=3&reset_context=1&ViewType=MENU_REQUEST&gui_open_popup=1&id_Window=5&activeWindowId=mw_5&noOrigUserDate=true&LocalDate=20220713&LocalTime=21061900&TimeZone=Asia/Shanghai&UserDate=0&UserTime=0&server_name=OPRISK_DATACOLLECTOR&key_id_list=&cell_context_id=0&id_Desktop=100237&operation_key=1000007&operation_sub_num=-1&is_json=1&is_popup=0&is_search_window=0&ccsfw_conf_by_user=0&is_batch=0&previousToken=1657717554097&historyToken=1657717579434&historyUrl=1'),
                        headers: {HttpHeaders.cookieHeader: newMessage},
                      );
                      ResponseModel responseModel =
                      ResponseModel.fromJson(jsonDecode(response.body));

                    final listNode = responseModel.response.genericListAnswer.listNode;

                    Map<String, dynamic> tableMessages = {
                      for (final json in listNode.map((x) => x.toJson()).where((json) => json['field'][5]['field_value'] == 'Loss Event'))
                        "Message": json['field'][0]['field_value'],
                    };

                    await WriteCache.setString(key: 'cache3', value: tableMessages['Message']);
                    print(tableMessages);

                      Navigator.of(context).push(MaterialPageRoute(
                          builder: (context) =>  messageBoard()));

                    }

I am printing the intended message successfully :

I/flutter (27053): {Message: There are 1 Loss Event currently in the status LE110 - Pending Approval}

but this is what I see on the device :

and here is the code to display the list :

body: Row(
        children: [
          Expanded(
            child: FutureBuilder(
              future: ReadCache.getString(key: "cache3"),
              builder: (context, snapshot) {
                if (snapshot.hasData) {
                  return ListView.builder(
                      itemCount: snapshot.data.length,
                      itemBuilder: (context, index) {
                        return Padding(
                          padding: const EdgeInsets.all(5.0),
                          child: ListTile(
                            title: Text(
                                snapshot.data[index],
                              style: GoogleFonts.poppins(
                                textStyle : const TextStyle(
                                  fontWeight: FontWeight.normal,
                                  fontSize: 20,
                                ),
                              )
                            ),
                            tileColor: Colors.blueGrey[200],
                            shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(10)),
                          ),
                        );
                      });
                } else {
                  return const Text("No Data");
                }
              },
            ),
          ),
        ],
      ),

how do I display the response normally instead of separate elements like in the image provided? Thanks.

Answer 1

cache3 is storing just a string, ie the Message string. In the itemCount property the length of the Message string is assigned as the number of items. Just change it to 1 and change the way it's accessing the text too.

It's going to be like the following:

body: Row(
        children: [
          Expanded(
            child: FutureBuilder<String>(
              future: ReadCache.getString(key: "cache3"),
              builder: (context, snapshot) {
                if (snapshot.hasData) {
                  return ListView.builder(
                      itemCount: 1,                     // <- Here
                      itemBuilder: (context, index) {
                        return Padding(
                          padding: const EdgeInsets.all(5.0),
                          child: ListTile(
                            title: Text(
                              snapshot.data,            // <- Here
                              style: GoogleFonts.poppins(
                                textStyle : const TextStyle(
                                  fontWeight: FontWeight.normal,
                                  fontSize: 20,
                                ),
                              )
                            ),
                            tileColor: Colors.blueGrey[200],
                            shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(10)),
                          ),
                        );
                      });
                } else {
                  return const Text("No Data");
                }
              },
            ),
          ),
        ],
      ),

On the other hand, if the intention was to have multiple messages the way they are populated should be changed as the last one will always win.

    List<String> messages = [
      for (final json in listNode
          .map((x) => x.toJson())
          .where((json) => json['field'][5]['field_value'] == 'Loss Event'))
        json['field'][0]['field_value'],
    ];

And save/restore it as a string list:

await WriteCache.setStringList(key: 'cache3', value: messages);

    future: ReadCache.getStringList(key: "cache3")