【问题标题】:type '_InternalLinkedHashMap<dynamic, dynamic>' is not a subtype of type 'List<Map<String, dynamic>>' of 'function result'类型“_InternalLinkedHashMap<dynamic, dynamic>”不是“函数结果”的“List<Map<String, dynamic>>”类型的子类型
【发布时间】:2021-04-14 13:06:30
【问题描述】:

在写这个问题之前,我已经查看了以下链接:

代码:

List data = [
    {
      "title" : "Particulate matter",
      "desc" : "The term used to describe a mixture of solid particles and liquid droplets found in the air",
      "amt" : 500,
      "diseases" : "Particulate matter is responsible for asthma in many people. Also, a topic dermatitis, allergic rhinitisare diseases that can be caused by this",
      "precaution" : "Switching to cleaner appliances and reducing the amount of smoking will surely ensure less exposureof particulate matter in the environment",
      "image" : 'https://images.pexels.com/photos/3668372/pexels-photo-3668372.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=750&w=1260',
      "color" : Color(0xFF6E7E5D).withOpacity(.3)
    },
// loads of data in this structure
];

// the line of error
Map indexedData = Map<String, dynamic>.from(data[index]);

我只是不知道为什么会出现错误,所以请帮助我。谢谢!

编辑:如果这有助于解决问题,我可以将数据更改为限制

【问题讨论】:

  • 实际代码而不是损坏的元代码怎么样?
  • 我已经用实际数据更新了,请查收
  • 索引中有什么?我希望为零。
  • 它实际上在ListView.builder 下,如果你愿意,我可以将其添加到问题中
  • 该错误指向哪一行?你展示的任何东西似乎都不可能。

标签: list flutter dart hashmap


【解决方案1】:

你应该像这样声明类型:

Map<String, dynamic> indexedData = Map<String, dynamic>.from(data[index]);

【讨论】:

    【解决方案2】:
    List data = [
        {
          "title": "Particulate matter",
          "desc":
              "The term used to describe a mixture of solid particles and liquid droplets found in the air",
          "amt": 500,
          "diseases":
              "Particulate matter is responsible for asthma in many people. Also, a topic dermatitis, allergic rhinitisare diseases that can be caused by this",
          "precaution":
              "Switching to cleaner appliances and reducing the amount of smoking will surely ensure less exposureof particulate matter in the environment",
          "image":
              'https://images.pexels.com/photos/3668372/pexels-photo-3668372.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=750&w=1260',
          "color": Color(0xFF6E7E5D).withOpacity(.3),
        },
      ];
    
      Map<String, dynamic> indexedData = {};
    
      data.forEach((mapElement) {
        Map map = mapElement as Map;
        map.forEach((key, value) {
          indexedData[key] = value;
        });
      });
    
    print(indexedData);
    

    【讨论】:

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