每次访问时，F＃静态成员都会更改

Question

这是一个非常简单的静态属性类：

[<AbstractClass; Sealed>]
type test () = 
    static member ttc = (new Random()).Next()

当我访问ttc时，它总是会改变......像这样:(在fsi.exe中）

我的目的是将值存储在静态成员中：

type typDimTablesArray () = 
static member DimApplication        = typDimTables.DimApplication      |> Seq.toArray
static member DimApplicationState   = typDimTables.DimApplicationState |> Seq.toArray
static member DimDatetime           = typDimTables.DimDatetime         |> Seq.toArray
static member DimDbQuery            = typDimTables.DimDbQuery          |> Seq.toArray
static member DimDeveloper          = typDimTables.DimDeveloper        |> Seq.toArray
static member DimPlatform           = typDimTables.DimPlatform         |> Seq.toArray

但每次我访问typDimTablesArray.DimDatetime.Length 它只是再次查询数据库，从不将数据存储在静态成员中......

Answer 1

以下是差异的简短示例：

type Test3() =
    let random = new System.Random()
    let y = random.Next()
    member __.X = random.Next()
    member __.Y = y
    static member val Z = (new Random()).Next()

let x = Test3()

x.X 
x.X
x.Y
x.Y
Test3.Z
Test3.Z

此外，您可以创建一个类型的实例并传入您需要处理的任何对象。现在如果它是懒惰的你可能需要缓存它：

let rnd = new System.Random()
let rnds = Seq.init 10 (fun _ -> rnd.Next())

type Test4(rndsX:int seq) =
    let xx = rndsX |> Seq.cache
    member __.Length = xx |> Seq.toArray |> Seq.length
    member __.First = xx |> Seq.head
    member __.Last = xx |> Seq.last