Flutter用递归遍历并查找子项

Map<String, dynamic> values = {
  '1': <String, dynamic>{
    '1-1': '1-1-value',
  },
  '2': <String, dynamic>{
    '2-1': '2-1-value',
    '2-2': <String, dynamic>{'2-2-1': '2-2-1-value'}
  },
  '3': <String, dynamic>{
    '3-1': '3-1-value',
  },
};

var findedValue = findMapValue('2-2-1',values);

///查找字段的值
dynamic findMapValue(String keyName, Map<String, dynamic> map) {

const String findedKeyName = 'finded';
const String valueKeyName = 'value';

Map<String, dynamic> recursiveFind(String fieldApiName, Map<String, dynamic> fieldValues) {
  for (var entry in fieldValues.entries) {
    if (entry.key == fieldApiName) {
      return {findedKeyName: true, valueKeyName: entry.value};
    }

    var value = entry.value;
    if (value is Map<String, dynamic>) {
      Map<String, dynamic> returnValue = recursiveFind(fieldApiName, value as Map<String, dynamic>);
      if (returnValue[findedKeyName]) {
        return returnValue;
      }
    }
  }

  return {findedKeyName: false, valueKeyName: null};
}

Map<String, dynamic> findResult = recursiveFind(field, map);
return findResult[valueKeyName];
}