flutter - 为什么 .contains 不 checkin List<Map> ？

Question

功能:

var mapList = [
  {"id": "1", "name": "zein"},
  {"id": "2", "name": "john"},
];

print(mapList.contains({"id": "1", "name": "zein"}));

结果:假

该列表实际上包含该值。为什么还是假？

Answer 1

根据@enzo的建议，您可以使用mapEquals来比较两个 map 对象:

import 'package:flutter/foundation.dart';

void main() {
  var mapList = [
    {"id": "1", "name": "zein"},
    {"id": "2", "name": "john"}
  ];

  var toCheck = {"id": "1", "name": "zein"};

  print(mapList.any((e) => mapEquals(e, toCheck))); // true
  
}

或者，您可以迭代列表并检查为:

mapList.forEach((e) {
  print(mapEquals(e, toCheck));
});