如何在颤动中从json中只选择一项答案

【问题标题】：how to select just one item from json in flutter如何在颤动中从json中只选择一项
【发布时间】：2021-06-26 02:29:01
【问题描述】：

您好，我想在我的应用程序中显示 SPX 价格，并且有这个 json API 我需要从这个 API 中选择 SPX 数据我该怎么做？？

    [{"ask":"28.47500","bid":"27.47500","name":"USDUAH","time":"1616772920.000"},

{"ask":"3972.06000","bid":"3971.16000","name":"SPX","time":"1617047940.000"},

{"ask":"0.71965","bid":"0.71916","name":"AUDCHF","time":"1617076421.403"}]]

【问题讨论】：

标签： json api flutter dart flutter-test

【解决方案1】：

这可能有效

List data = parseResponse(response.body)
var spx ;
data.forEach((element) {
        if (element["name"]=="SPX"){
           spx =element; // access the spx object to get other data
         }
        });

static List<Trade> parseResponse(String responseBody) { // for converting array of objects to object list
      final parsed = json.decode(responseBody).cast<Map<dynamic, dynamic>>();
      return parsed.map<Trade>((json) => Trade.fromJson(json)).toList();
    }```

【讨论】：

【解决方案2】：

你可以这样做：

final lst = [{"ask":"28.47500","bid":"27.47500","name":"USDUAH","time":"1616772920.000"},
{"ask":"3972.06000","bid":"3971.16000","name":"SPX","time":"1617047940.000"},
{"ask":"0.71965","bid":"0.71916","name":"AUDCHF","time":"1617076421.403"}];

final res = lst.where((element) => element['name'] == 'SPX').toList();

查看 DartPad here 上的完整示例

【讨论】：