Xamarin.iOS 中的 iOS 选择器

Question

I am trying to create an UIAccessibilityCustomAction in Xamarin.iOS. This method require name, target, selector as arguments (as you can see here ). The problem is with the selector argument.

In Xcode (using Swift) I can easily implement it like this:

let up = UIAccessibilityCustomAction(name: "Increment", target: self, selector: #selector(increment))


@objc private func increment() -> Bool{
    //selector implementation
}

In Xamarin (using C#) I tried that:

UIAccessibilityCustomAction up = new UIAccessibilityCustomAction(name: "Increment", target: iospage, selector: new Selector("Increment"));

And its being said that Selector can take both a String or a IntPtr as argument. Since I have no idea what IntPtr is and how should I use it, I tried to use the String parameter, as you can see above, and I tried to implement the selector like this, following this answer .

[Export("Increment")]
    private void Increment()
    {
        //selector implementation
    }

Problem is that seems like this method never got called (i tried to make it log something when the UIAccessibilityCustomAction is called, but no log is shown), probably because it is the wrong way to implement it.

Any idea?

Thanks

Answer 1

UIAccessibilityCustomAction has another instantiate method which you can pass an custom action into it.

 UIAccessibilityCustomAction c = new UIAccessibilityCustomAction("Increment", 
        (UIAccessibilityCustomAction customAction) =>
        {

               //selector implementation
        });

Answer 2

Thanks to the tip of @Cole Xia - MSFT, I found another instantiate method that seems to be easier to handle, using only name, actionHandler , so without a target and selector . actionHandler is easier to use, cause it's only a function that needs a bool return type.

My implementation:

UIAccessibilityCustomAction up = new UIAccessibilityCustomAction("Increment", actionHandler: Increment);

private bool Increment(UIAccessibilityCustomAction customAction)
{
    //implementation of the handler
}