HowTo cast a declare returned Ptr to custom class?

Targets macOS
1

Another declare question.
I have a method returning a Ptr like this one:

Function resultAtIndex(index as integer) As Ptr declare function resultAtIndex lib "Cocoa" selector "resultAtIndex:" (class_id as ptr, index as integer) as Ptr return resultAtIndex(self, index) End Function
This is a methond from NSMetadataQuery returning a NSMetadataItem.
Now I have a custom class “NSMetadataItem” and I want to assign the returned Ptr to that class.
Unfortunately it does not work just using

dim NSMetadataItemRef as NSMetadataItem = me.resultAtIndex(index)

and I had no success via casting or what ever I tried (I even looked at the help page for Ptr!).

Any idea how to give the returned Ptr the proper type?

TIA,

Thomas

2

A Ptr is a Ptr is a Ptr.

The only thing you could do is wrap the Ptr in your NSMetadataItem class, for example via a Constructor with a Ptr as parameter. Then you can do:

Dim NSMetadataItemRef As New NSMetadataItem(Me.resultAtIndex(index))
3

This is in exactly what I want. Unfortunately I habe currently no idea how i can do this…
Can you give me an example?

4

[code]Class NSMetadataItem

Private Property mPtr As Ptr

Sub Constructor(p As Ptr)
mPtr = p
End
…[/code]

5

Ah, now I see what you mean. This is of course always possible but not wat I want here.

The returned Ptr is in fact a pointer to a NSMetadataItem instance. So I want to tell Xojo that. Any other idea?

6

You can’t tell Xojo that beyond doing as Eli suggested. That’s exactly how it is handled in MacOSLib and iOSKit and other libs…

7

Oh I see.
So that is the way to proceed. I thought there would be a easier way to cast a Ptr to any class instance which would be handy for declare usage.

Thanks for your help.