Question

我尝试将C＃代码转换为F＃

Items = new List<Item>
{
    new Item
    {
        Product = "",
        Category = "",
        Quantity = 1,
        Detail = "",
        Price = 220
    }
}

按照代码F＃：

let items = ResizeArray<Item>()
items.Add(Item(
            Product = "", 
            Category = "", 
            Quantity = 1, 
            Detail = "", 
            Price = 220))
let body = 
    OrderRequest(
        Items = items)

如何直接在Items属性中实例化？无需创建新变量，然后创建一个Add()。等于第一个C＃代码。

我已经尝试过这种方法，但是它不起作用：

let body = 
    OrderRequest(
        Items = ResizeArray<Item>(Item(
                                    Product = "", 
                                    Category = "",
                                    Quantity = 1,
                                    Detail = "",
                                    Price = 220)))

我得到一个错误：

Error FS0193 Possible overhead: 'Generic.List (collection:
Generic.IEnumerable <Item>): ResizeArray <Item>'. 
Incompatible type restrictions. The 'Item' 
type is not compatible with
type 'Generic.IEnumerable <Item>'

Answer 1

如果Items的类型为IEnumerable<Item>（又名Seq<Item>），则可以编写：

let body = 
    OrderRequest(
        Items =
            [ Item(
                Product = "", 
                Category = "", 
                Quantity = 1, 
                Detail = "", 
                Price = 220) ]
   )

Answer 2

如果OrderRequest构造函数使用IEnumerable<T>，则可以执行@VasilyKirichenko的建议。否则，如果实际上需要ResizeArray，我建议您阅读以下内容：

let body =
    seq { Item (Product = "",
                Category = "",
                Quantity = 1,
                Detail = "",
                Price = 220) }
    |> fun li -> ResizeArray<_> li
    |> fun ra -> OrderRequest (Items = ra)

属性中的ResizeArray实例

2 个答案: