Android Question does initializing a panel remove its child views?

[Dave O]

I have a panel that contains other views.

Normally, if I were to get rid of the panel (e.g. with RemoveView), I would first remove all of its child views using RemoveAllViews.

But what happens if I just leave the panel there (for later reuse), and later initialize it again (and re-add it to the activity)? What happens to its former child views? Are they effectively removed from it as if I had done a RemoveAllViews? Or do they get stuck in limbo?

The latter is what my current code does, and I'm OK with leaving it that way if I'm not leaving zombie views lying around.

 

[klaus]

Panel1.RemoveView removes the Panel with all its child views!
If you only reinitialize and re-add the Panel you generate a new instance of the Panel which means a new Panel. The previous Panel with all its views remains.
If you do this 10 times you will have 11 Panels !
If you want to keep the Panel but remove its child views you must use Panel1.RemoveAllViews.

 

[Dave O]

Thanks @klaus .

Two more follow-up questions, just so I'm clear:

> Panel1.RemoveView removes the Panel with all its child views!

Is this the same as doing panel1.RemoveAllViews followed by panel1.RemoveView? If so, it's a nice shortcut.

> If you only reinitialize and re-add the Panel you generate a new instance of the Panel which means a new Panel. The previous Panel with all its views remains.

Is this also true for class instances in general, not just views? In other words, if I re-init an object, does the old object still exist with all its contents, or does it get garbage-collected at some point?

Thanks again!

 

[Informatix]

Panel1.RemoveView removes the Panel with all its child views!

Is this the same as doing panel1.RemoveAllViews followed by panel1.RemoveView? If so, it's a nice shortcut.

It's not exactly the same thing from the GC point of view but in practice that doesn't make a real difference.

Is this also true for class instances in general, not just views? In other words, if I re-init an object, does the old object still exist with all its contents, or does it get garbage-collected at some point?

It depends on what is behind Initialize. So it depends on the developer who wrote the class/library. Creating an instance is done by Dim, so Initialize should not be used to create a new instance. But the fact is that Initialize is often used to create an underlying instance in a wrapper. For example, the ArrayList object, which is the Java object behind a list, is created when you call List.Initialize.