当我们在子列表上应用条件时如何过滤父列表<>？

Question

当我们对子列表应用条件时如何过滤父列表？

public class VendorEntities
{
    public int VendorId { get; set; }     
    public string VendorName { get; set; }
    public List<ItemEntities> ItemDealdetails { get; set; }    
}

public class ItemEntities
{
    public int ItemId { get; set; }
    public string ItemName { get; set; }
    public int TenantId { get; set; }
}

List<VendorEntities> objVenderList = new List<VendorEntities>();
objVenderList = objVendorBL.GetVendorName();

var rList = (from a in objVenderList
             from b in a.ItemDealdetails
             where b.ItemName.Contains("Computer")
             orderby a.VendorName descending
             select a).ToList().Distinct();

现在我想搜索那些ItemName 包含Computer 的供应商，它存储在子列表ItemEntities 中。我怎么能这样做？请给我一些建议。

Answer 1

你可以使用Enumerable.Any:

var rList = objVenderList
        .Where(v => v.ItemDealdetails.Any(d => d.ItemName.Contains("Computer")))
        .OrderByDescending(v => v.VendorName)
        .ToList();

请注意，我省略了您的 Distinct，因为它只会删除重复的引用，直到您尚未实现 IEquatable<T> 或覆盖 Equals + GetHashCode。

这里查询语法相同：

var filteredByItemNameComputer = 
    from vendor in objVenderList
    where vendor.ItemDealdetails.Any(d => d.ItemName.Contains("Computer"))
    orderby  vendor.VendorName descending
    select vendor;
var rList=filteredByItemNameComputer.ToList();