Spinner and ListPicker advantages

[DenPit5]

Can anyone  tell what are the differences and advantages of the Spinner and ListPicker.      To me they both seem to perform in a similar way.

[Enis]

Definitely different in that a Spinner can occupy a segment of the screen, while a Listpicker is ALWAYS full screen.

[DenPit5]

Thanks Enis for reply.         If ones sets the Spinner to 'hidden' how does one invoke it into 'visible'.   Also can you specify where it should appear and can this be infront of say a Canvas and does it then disappear when a selection is made.?

[Stephen Zipprich]

Thanks Enis for reply.         If ones sets the Spinner to 'hidden' how does one invoke it into 'visible'.   Also can you specify where it should appear and can this be infront of say a Canvas and does it then disappear when a selection is made.?

Part of what makes App Inventor fun is trying things out and seeing what does and doesn't work.  Perhaps you can experiment to answer your own questions.  Connecting to the emulator or a phone using the companion app means you don't have to package your app and install it just to test things out. 

[Taifun]

see also tip 2

https://puravidaapps.com/learn.php

Taifun

[DenPit5]

Thanks Stephen and Taifun.    I have tried some experimenting as you suggested but I still am unable to get  the Spinner to behave in the way I would like.     I Initially want the Spinner to be hidden and then On a Button-Click to become visible with no item selected.    When an item is selected I need the Spinner to become hidden again.  I have tried setting it to visible and using the 'Call GetShape.DisplayDropdown' call but the first item in the list always seem to be selected.when it appears.   I have also tried setting SelectionIndex to 0 but it seems to be ignored.     Any help that anyone can give would be  gratefully received.

[Taifun]

When an item is selected I need the Spinner to become hidden again.

to set a spinner to hidden, just set spinner.visible to false

It would really help if you provided a screenshot of your relevant blocks, so we can see what you are trying to do, and where the problem may be.

Taifun

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Trying to push the limits of App Inventor! Snippets and Tutorials from Pura Vida Apps by Taifun.         

[DenPit5]

Thanks for reply Taifun.       The problem seems to be that the Spinner always seems to open up with the first item in the list already selected so it goes straight on to the 'AfterSelection' routine.  I attach the relative blocks below.

[Taifun]

this seems to be a bug, which has been reported here https://groups.google.com/d/msg/mitappinventortest/TB1iTPwvBn4/41svzFX3_sYJ

just follow Hossein's advice meanwhile

Taifun

[DenPit5]

Thanks Taifun for the link.       I have looked at it and incorporated  what was described there in my APP and it now works correctly.    Any idea when this bug wil lbe corrected in AI2

[Taifun]

as soon as possible, and this is valid for all bugs ;-)

Taifun