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A way to return the name of the control that currently has focus?
- Thread starter Tex8503
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So after doing a bit more research, it seems like this isn't built into the compact framework... The full blown .NET way would be to call Form.ActiveControl
However, after some googleing it looks like some people like on this site (Software Development and stuff: Getting ActiveControl in Compact Framework) have come up with code to emulate this feature...
Anyone wanna take a stab at turning this into a library ?
:sign0163:
However, after some googleing it looks like some people like on this site (Software Development and stuff: Getting ActiveControl in Compact Framework) have come up with code to emulate this feature...
Anyone wanna take a stab at turning this into a library ?
:sign0163:
Most of the "visual" controls has an event called "GotFocus", triggered when the control ...well...get the focus, and another called "LostFocus"...I bet you know waht that means...
I know its a nag to code a couple dozen GotFocus events to known wich got the focus, but with some code "teaks a tricks" I bet you can come up with a couple of lines of code to pull it out.
I know its a nag to code a couple dozen GotFocus events to known wich got the focus, but with some code "teaks a tricks" I bet you can come up with a couple of lines of code to pull it out.
But when would you use it? The subsequent discussion about events shows that when a focus event occurs that is the time to find which control is involved. Otherwise you are just proposing some random or timer event to enquire where the focus is, and the user could swop to another control in the next instant and invalidate the answer.
A single event Sub can be related to all appropriate controls (using a loop, perhaps) and then that single Sub can find which control has the focus. Presumably different actions would then be required (context menu or whatever).
Mike.
Actually - I do have a random event that this is useful for - My barcode scanner.
Rather than having to maintain 'gotfocus' events for each element - it'd be great if my scanning function could tell where focus was on demand to be able to plugin the data it has...
Rather than having to maintain 'gotfocus' events for each element - it'd be great if my scanning function could tell where focus was on demand to be able to plugin the data it has...
Well, perhaps, but that is not a common enough scenario for it to be an "intuitive" way of working.
Although I worked on a commercial system that included barcode scanning (for all sorts of purposes, not just merchandise), there was no similar link with the GUI.
So I think that coding as suggested using an event Sub is a reasonable solution.
Mike.
My objection to this method is that I don't think its just one sub event (correct me if I'm wrong...) but I'd need a sub event for every object that I want to detect if it has focus or not...
If there were one or two elements, that might be ok... but I could run into scenarios where it could be 20+ elements. That ends up just being a poor way to program it.
If there were one or two elements, that might be ok... but I could run into scenarios where it could be 20+ elements. That ends up just being a poor way to program it.
You do need to do an AddEvent for each control (hence I mentioned a loop), but can cite the same Sub and then use Sender (see the Help for Runtime control manipulation) to detect which control has received the focus.
Mike.
So... I was able to use one of Erel's examples to provide a decent solution that I'm satisfied with for this particular problem and figured I should share...
Check out Erel's example here: http://www.b4x.com/forum/questions-help-needed/4683-control-navigation-hardware-keys.html
You can use Hashtable1.Item(SelectedControl) to grab the name of the item that currently has focus. Yes - this does create gotfocus events for each item (which is less than desirable) - but this is a bit more clean than doing them each by hand...
This fixed another issue I was having with items not tabbing in the correct order (or at all...) as I was able to capture the tab button when pressed on the form and I'm using this code that Erel wrote to change focus to the next form element.
Check out Erel's example here: http://www.b4x.com/forum/questions-help-needed/4683-control-navigation-hardware-keys.html
You can use Hashtable1.Item(SelectedControl) to grab the name of the item that currently has focus. Yes - this does create gotfocus events for each item (which is less than desirable) - but this is a bit more clean than doing them each by hand...
This fixed another issue I was having with items not tabbing in the correct order (or at all...) as I was able to capture the tab button when pressed on the form and I'm using this code that Erel wrote to change focus to the next form element.