如何在函数的静态变量中设置属性

Question

In this case the static variable textView is contained in Holder struct.
But I encountered a problem that I have to set "Holder.textView.fieldEditor = true" every time when user invoke this function.
How do I let this action only run once?

func myTextView() -> NSTextView {

    struct Holder {
        static var textView = NSTextView()
    }

    Holder.textView.fieldEditor = true
    return Holder.textView
}

Answer 1

This

struct Holder {
    static var textView = NSTextView()
}

should be defined outside the scope of your function. Otherwise each time you call myTextView() a new Holder struct is defined and instantiated.

This makes the static var useless for your purpose.

On the other hand, if you define Holder outside the function the value does persist among multiple calls.

Look