如何在 Dart 中过滤列表？

Question

can some one help me to filter a List that i need to use for gridview.builder where a category name is passed also device id if no category is given my problem is list has same categorized device so i need to filter similar category so the grid has distinct category

List<Device> _deviceList = [
  Device('id':'d1', 'Name':'Fan', 'Category':'LivingRoom'),
  Device('id':'d2', 'Name':'Tv', 'Category':'LivingRoom'),
  Device('id':'d3', 'Name':'Light', 'Category':''),
  Device('id':'d4', 'Name':'refrigerator', 'Category':'Kitchen'),
];
// i need to filter this so only one livingroom and any other similar category should come only once in gridview 

Answer 1

I would suggest you this steps: first define a class for Device:

class Device{
  String id;
  String name;
  String category;
  
  Device(this.id, this.name, this.category);
}

then filter the given list as follow:

List<Device> _deviceList = [
  Device('d1', 'Fan', 'LivingRoom'),
  Device('d2', 'Tv', 'LivingRoom'),
  Device('d3', 'Light', ''),
  Device('d4', 'refrigerator', 'Kitchen'),
];

String selectedCategory = "LivingRoom";
  
  List<Device> temp = _deviceList.where((element)=>element.category==selectedCategory).toList();