TOPIC:

The last few weeks I've been working with some Winforms VOXported from VO forms.

In VO we use EditFocusChange to set a class variable telling which control got focus.
I have not yet understood how this works in X# WInforms.

I tried adding an individual method for each control for which the program needs to be aware of when it gets focus:

But I am not sure how to register the event handler (which I did in C# programs). I tried this in the constructor:

but then I get:

Error XS0407 'usual MyPrg.textBoxTo_GotFocus(object, System.EventArgs)' has the wrong return type

What should I do differently?

Or did I miss a Winforms equivalent of EditFocusChange ?

Dick

Hi Dick,
the C# documentation says this:and traduced to X# it would beSo you are missing the return type "as void".
Personally, I would build my own control class inherited from the textbox class and add that method there, and eventually call a "EditFocusChange" method in the window itself.
Wolfgang
P.S. I don't know if VS helps in this, but XIDE optionally creates this method automatically

Hi Wolfgang,

wriedmann wrote:

P.S. I don't know if VS helps in this, but XIDE optionally creates this method automatically

It does? How? Must have been another feature that I implemented and totally forgot about!

.

Hi Chris,
it does, and indeed it is very helpful!


Step1:



Step2:



Step3:


Wolfgang

Hi Wolfgang,

Ah, thanks, now I understood what you meant!

Hi Chris,
as I wrote: this is very helpful and I use it several times to see what the prototype on an event handler is, even if I don't use the code as it is written by XIDE, because the "Eventhandler" syntax is not needed anymore in most cases.
Wolfgang

Hello Wolfgang,

wriedmann wrote:

So you are missing the return type "as void".

There was no problem there. With or without a void, Method textBoxTo_GotFocus isn't fired when I enter the textBoxTo.

Hence I thought I had to register an event handler for it (never sure when I need to to that and when not...) and it is there were I got the error.

I've tried multiple alternatives:

1 Private Method textBoxTo_Enter
2 Private Method textBoxTo_Leave
3 Private Method textBoxTo_Validating
4 textBoxTo_TextChanged

Only 4) is actually working when I type something in that textbox but that is not what is needed here.


For 1&2 Microsoft states in learn.microsoft.com/en-us/dotnet/api/sys...w=windowsdesktop-6.0:

The Enter and Leave events are suppressed by the Form class. The equivalent events in the Form class are the Activated and Deactivate events.

No idea why and even less why Activated/Deactivated, which are fired (or at least documented to do so) when the whole window gets or loses focus, are indicated as alternative.

Bottom line is that there doesn't seem to be any working even which is fired when I enter a control on a Winforms window.

So if anyone has an idea of way or alternative event which actually works, that would be great.

Dick

Hi Dick,
for me this works:
And here is the application, based on the XIDE sample Windows Forms app:

I'm sorry, you have to import that file in XIDE, I don't like to transport it to Visual Studio.
Wolfgang

Hi Dick,
I think you misunderstand the doc :
When using Control, the fired events are Enter & Leaver
Form is inheriting from Control, so we should have Enter/Leave also, but at that level, the fired events are Activated/Deactivate.

Now, the GotFocus Event doesn't exist with Windows Forms, you have to use Enter there.
In order to link an Event to a Method, I suggest you use the integrated mechanism of VS :
Select the control, go to the Properties Window, and click on the Event button (Lightning) to switch to the event panel.
Then scroll down to the desired event and double-click on it : The X# integration will generate the needed skeleton, create the link-code and open the editor in the corresponding method.
!!! NEVER suppress the generated skeleton if you have made a error... VS generate the code, so you have to remove it FROM VS.
Follow the same process, but instead to double_clicking on it, Right-Click and select Reset in the context menu.

Now, If you want to check the events and their firing order, I have created a small demo app for you, it is attached to this message.

HTH,
Fab

Hello Wolfgang, Fabrice,

wriedmann wrote:

for me this works:
[code]self:oField1:GotFocus += self:Field1GotFocus

Thank you very much for your efforts and I can tell you that it works (even if not generated from VS). It does need registering the event but now I am lost why it gave the Error XS0407. Only difference seems the missing 2nd self compared to your registering code but when I uncommented my original registering code it still compiled. And it honestly did not this morning.

Never mind, it compiles and it works now as it should. Later I may need Leave/Enter and then I will have Fabrice's sample to implement it.

Thanks again!

Dick

Hi Dick,
in .NET every event needs to be registered - and it can also be de-registered.
This concept has the advantage that you can call your callback method how do you like it, you can register more than one callback for every control, and you can register the same callback on different controls.
But, if you have learned the VO lessons, you can also create your own subclass (I have done that for the pushbutton class):Wolfgang