Public Mutable Field in Object

问题

Is it possible to create a simple public mutable field in F#? I'm creating a library that I will be accessing from a C# program and I need to be able to set a field from C#.

//C# Equivalent 
public class MyObj
{
    public int myVariable;
}

//F#
type MyObj = 
    //my variable here

    member SomeMethod() = 
        myVariable <- 10

//C# Usage
MyObj obj = new MyObj();
obj.myVariable = 5;
obj.SomeMethod()

回答1:

type MyObj() = 
    [<DefaultValue>]
    val mutable myVariable : int
    member this.SomeMethod() = 
        this.myVariable <- 10

You can leave off [<DefaultValue>] if there's no primary constructor, but this handles the more common case.

回答2:

How about:

[<CLIMutable>]
type MyObj = 
    { mutable myVariable : int }
    member x.SomeMethod() = 
        x.myVariable <- x.myVariable + 10

Then you can do:

var obj = new MyObj();
obj.myVariable = 5;
obj.SomeMethod();

or

var obj = new MyObj(5);
obj.SomeMethod();

来源：https://stackoverflow.com/questions/24670719/public-mutable-field-in-object