list - ListView 使用Flutter中的属性过滤掉最后一行数据

Question

我有一个列表，其中包含项目名称，索引和计数。现在有不止一个项目具有相同的索引，但是我想将它们过滤到一个新的List中，该列表仅包含每个索引的最后一行数据。

例如，如果我的列表如下:

ALPHa  index 0 and count is 2
ALPHa  index 0 and count is 3
ALPHa  index 0 and count is 4
ALPHa  index 0 and count is 5
ALPHa  index 0 and count is 4
ALPHa  index 0 and count is 3
ALPHa  index 0 and count is 2
ALPHa  index 0 and count is 1
ALPHa  index 0 and count is 5
ALPHa  index 0 and count is 0
BETA  index 1 and count is 1
BETA  index 1 and count is 2
BETA  index 1 and count is 3
BETA  index 1 and count is 4
BETA  index 1 and count is 3
BETA  index 1 and count is 2
BETA  index 1 and count is 3
BETA  index 1 and count is 4
DELTA  index 2 and count is 4
DELTA  index 2 and count is 1
DELTA  index 2 and count is 2
DELTA  index 2 and count is 3

过滤后的列表应该像

ALPHa  index 0 and count is 0
BETA  index 1 and count is 4
DELTA  index 2 and count is 3

有人可以告诉我如何将其过滤掉吗？

我的代码如下:

模态课:

class CartItems {
  String itemname;
  int numberofitems;
  int index;

  CartItems({
    this.itemname,
    this.numberofitems,
    this.index
  });
}

list

List <CartItems> cartItems = List();
for(int i =0; i < itemList.length; i++) {
   cartItems.add(CartItems(itemname: itemList[i].itemname, numberofitems: itemList[i].numberofitems,index:index));
}

Answer 1

试试这个代码。
将您的原始列表作为参数传递给该方法，该方法将返回过滤的 CartItems 列表。

List<CartItems> filterList(List<CartItems> itemList){
    int currentItemsIndex = 0;
    CartItems cartItem;
    List < CartItems > cartItems = List();
    for(int i =0 ;i< itemList.length; i++) {
      cartItem = CartItems(itemname: itemList[i].itemname, numberofitems: itemList[i].numberofitems,index:itemList[i].index);
      if(currentItemsIndex == itemList[i].index){
        if(i == itemList.length-1){
          cartItems.add(cartItem);
        }
      }else{
        cartItems.add(cartItem);
      }
      currentItemsIndex = itemList[i].index;

    }
    return cartItems;
  }