Vertical list for creating Menu: change SelectedItem property from a generated function, from outside

Question

Hallo,

i have a vertical list with 4 items, and i want to switch the selecteditem property from my generated slot method. I have a menu item class too, which makes a border arround the item to highlight it ( which works).

I simply just want to increment the selectedItem property with the slot method (which i generated to call from outside). When i press a button on my screen (not touch button) the slot method is called and should seelct the next item.

In my Opion it should just work with: Verticallist.SelectedItem++, but then i get a memory error which want to access to to a space which not exist. In other words i cant change the property SelectedItem from outside.

i tried sth with UpdateViewState but it dont works.

Do anyone have an idea ?

Answer 1

Hello Pablo,

the operation Verticallist.SelectedItem++ is the correct approach to adapt the selection within the vertical list. Triggering the operation from the 'outside' of the GUI application should also work. In your question, however, you mention a memory error. I assume, you get a CPU exception.

Question 1: Is your application using multiple threads?

Question 2: Is the code containing  Verticallist.SelectedItem++ called from an external thread?

Please note: the entire GUI related code may be called only in context of the GUI thread. No other thread may call the Embedded Wizard functionality. See also: Take care in multi-threading environments.

Question 3: How does the 'outside' code call the Embedded Wizard code?

Question 4: Do you have a debugger in the target system? If yes, can you provide more details concerning the location where the exception occured?

Best regards

Paul Banach

Comments

Hello,

Q1 + Q2: Its just one thread.

Q3: FIrst i call the Embeeded Wizard method to show my list on the screen, and it works correctly. Then i press a button and the method to switch the selected item is call. The error dont come at the method call, it comes later when processSignals is called.

Q4: Yes i do. Location description: CoreLineView_MoveView()

Thank you for your help

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Hello Pablo,

can you show the corresponding C code where you invoke Embedded Wizard code?

Best regards

Paul Banach

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Hello,

thank you for your help,

we find the problem..

we used the wrong context parameter.. Now it works!

 

Wish you a nice week

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Hello Pablo,

thank you for the good news.

Best regards

Paul