c# - 我如何在 C# 中做到这一点？

Question

结构是

• 产品有一个类别列表。
• 类别有一个 pieceinfo 列表
• 每个 pieceinfo 都有一个 Id，我想检查它是否存在于产品中。

我有一个列表 int List<int> pieceinfo我想从 List<product> 得到.

谁能告诉我该怎么做？

我想写一个lambda expression检查是否pieceinfo存在与否。

Model.Find(x => x.Categories.Find(y => y.PieceInfo.Find(z => z.Id == i)))

我想知道如何检查每个产品的类别' pieceinfo有一个 Id这也存在于 list<int> i 中.

public struct Product
{
    public int Id;
    public string Title;
    public List<Productdetailed> Info;
    public List<ProductCategory> Categories;
}

public struct ProductCategory
{
    public int Id;
    public string Title;
    public bool Has_Image;
    public List<ProductInfo> PieceInfo;
    public int ProdId;
}

/// <summary>
/// Coverage, packing detailed
/// </summary>
public struct ProductInfo
{
    public int Id;
    public string Size;
    public string Packing;
    public string Price;
    public bool PricePerTon;
    public int ProdId;
    public int Cat_Id;
}

public struct Productdetailed
{
    public int Id;
    public string Packaging;
    public string Coverage;
    public int prodId;
}

Answer 1

var allPieces = Model.SelectMany(x => x.Categories).SelectMany(y => y.PieceInfo);
var isPieceExist = allPieces.Any(piece => piece.Id == id);

// or

var findedPiece  = allPieces.FirstOrDefault(piece => piece.Id == id);