我正在尝试为已绘制到表单中的2d对象创建一个保存/加载功能。
type circle = { X : int; Y : int; Diameter : int; Brush : Brush}
type Square = { X : int; Y : int; Length : int; Height: int; Brush : Brush}
当我创建对象时，我将它们放入每种类型的2个列表1中。我最初的想法是将这些对象读取并写入文本文件，请参见下文：
saveFile.Click.Add(fun _ ->
for c in listOfCircles do
myfile.WriteLine("Circle," + c.X.ToString() + "," + c.Y.ToString() + "," + c.Diameter.ToString() + "," + c.Brush.ToString())
for s in listOfSquares do
myfile.WriteLine("Square," + s.X.ToString() + "," + s.Y.ToString() + "," + s.Height.ToString() + "," + s.Length.ToString() + "," + s.Brush.ToString())
myfile.Close() // close the file
在文本文件中看起来像这样
Circle,200,200,50,System.Drawing.SolidBrush
Square,50,55,45,55,System.Drawing.SolidBrush
从这里我想读取这些值，然后能够解析它们，并通过将对象添加到列表中并重新绘制它们来重新创建对象。
let readCircle =
System.IO.File.ReadAllLines path
|> Array.choose (fun s ->
match s.Split ',' with
| [|x; y ; z ; b ; _|] when x = "Circle" -> Some (y, z, b)
| _ -> None )
let readSquare =
System.IO.File.ReadAllLines path
|> Array.choose (fun s ->
match s.Split ',' with
| [|x; y ; z ; b ; a ; _|] when x = "Square" -> Some (y, z, b, a)
| _ -> None )
这些功能给我
val readCircle : (string * string * string) [] = [|("200", "200", "50")|]
val readSquare : (string * string * string * string) [] = [|("50", "55", "45", "55")|]
我现在遇到的问题是我不确定如何从数组中获取值。下面是带有多个圆圈的示例。
val readCircle : (string * string * string) [] = [|("200", "200", "50"); ("200", "200","50")|]
非常感谢您关于如何从此处/如何解决此问题的任何想法或意见！问题摘要：如何从数组中获取值并将其放入例如我已经创建的添加函数中，请参见下文：
listOfCircles.Add({ X = 200; Y = 200; Diameter = 50; Brush = Brushes.Black})
您可以使用转换字符串数组的数组Array.map，例如
[|("200", "200", "50"); ("200", "200","50")|]
|> Array.map (fun (x,y,d) -> {X = int32 x; Y = int32 y; Diameter = int32 d; Brush = Brushes.Black})
如果您转换为circle或square解析文件时，可能会更清楚一点，那么您将拥有一个数组circle或一个数组square，可以直接将它们添加到列表中。
let readCircle =
System.IO.File.ReadAllLines path
|> Array.choose (fun s ->
match s.Split ',' with
| [|t; x; y; d; _|] when t = "Circle" ->
Some {X = int32 x; Y = int32 y; Diameter = int32 d; Brush = Brushes.Red}
| _ -> None )
但是...如果您想进行更大的更改，则可以使用区分的并集来表示形状，然后它们将共享一种通用类型，Shape并且可以在同一函数中解析圆形和正方形。
type Shape =
| Circle of X : int * Y : int * Diameter : int * Brush : Brush
| Square of X : int * Y : int * Length : int * Height: int * Brush : Brush
let readShapes (data: string array) =
data
|> Array.choose (fun s ->
match s.Split ',' with
| [|t; x; y; d; _|] when t = "Circle" ->
Some (Circle(X = int32 x, Y = int32 y, Diameter = int32 d, Brush = Brushes.Red))
| [|t; x; y; l; h; _|] when t = "Square" ->
Some (Square(X = int32 x, Y = int32 y, Length = int32 l, Height = int32 h, Brush = Brushes.Red))
| _ -> None )
let listOfShapes = ResizeArray<_>()
let testInput = """
Circle,200,200,50,System.Drawing.SolidBrush
Square,50,55,45,55,System.Drawing.SolidBrush"""
testInput.Split('\n') // System.IO.File.ReadAllLines path
|> readShapes
|> Array.iter (listOfShapes.Add)
这将导致
val it : System.Collections.Generic.List<Shape> =
seq
[Circle (200,200,50,System.Drawing.SolidBrush {Color = Color [Red];});
Square (50,55,45,55,System.Drawing.SolidBrush {Color = Color [Red];})]
然后，您可以使用图案匹配来绘制每种形状
let drawShape shape =
match shape with
| Circle(x,y,d,b) ->
printfn "Pretend I just drew a circle at %d,%d with diameter %d." x y d
| Square(x,y,l,h,b) ->
printfn "Pretend I just drew a rectangle at %d,%d that was %d long and %d high." x y l h
listOfShapes |> Seq.iter drawShape
给予
Pretend I just drew a circle at 200,200 with diameter 50.
Pretend I just drew a rectangle at 50,55 that was 45 long and 55 high.
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