在F#类中,如何在初始化时在另一个值中使用一个值?

我试图复制有三个字典的C#代码:

Dictionary<string, float> DictionaryA = new Dictionary<string, float>();
Dictionary<string, float> DictionaryB = new Dictionary<string, float>();
Dictionary<MyEnum, Dictionary<string, float>> Dictionaries
    = new Dictionary<MyEnum, Dictionary<string, float>>();

在构造器中:

Dictionaries[MyEnum.A] = DictionaryA
Dictionaries[MyEnum.B] = DictionaryB

所以,在F#中,我这样做:

member val private DictionaryA = new Dictionary<string, float>()
member val private DictionaryB = new Dictionary<string, float>()

但是,在构造函数中,似乎“this”不可用:

do
    this.Dictionaries.Add(MyEnum.A, this.DictionaryA) |> ignore
    this.Dictionaries.Add(MyEnum.B, this.DictionaryB) |> ignore

行不通。

我如何初始化第三本字典?