Hi,
I have a problem whith the ultraGrid.I am editing a string field, and while still editing, I click outside the grid such as I gice the focus to another component.The gridLostFocus event is not raised. (If I am editing in an UltraNumericEditor it works fine).Is that a know problem, or do I do something wrong ?
Thanks
Anne-Lise
Hi Anne-Lise,
What component outside the grid are you clicking on? Not all components take focus. If you click on a toolbar button, for example, the grid will not lose focus.
In any case, I would strongly recommend that you do not use LostFocus or GotFocus events on any control. These events are tied directly to Windows messages and they will give you all sorts of unexpected results. Microsoft's documentation advises against using them in DotNet, also. You should use Enter and Leave, instead.
It occurs with different sort of components which take focus:
If I use a ultraNumericEditor to edit in my cell it works (Grid lostFocus is correctly sent), but if I use default behavior to edit in cell or a ultraTextEditor it does not works (Grid lostFocus is not sent when another component take the focus).
Hi Tanner,
Tanner Stevenson said: I realized that the Leave event doesn't get thrown with either editor, but the grid's lost focus event does get thrown with the UltraFormattedTextEditor.
Okay... well, that makes perfect sense and it's one of the main reasons why using the LostFocus event is NOT a good idea. LostFocus is tied to the Windows messages. When a grid cell with a FormattedTextEditor is in edit mode, the grid has focus. Therefore, when you click on some other control, the grid loses focus.
But, if the grid does not have focus, because it contains a child control (like a TextBox) which is what happens when a regular text cell has focus, the event will not fire. It doesn't fire because the grid didn't lose focus, because the grid didn't HAVE focus. The TextBox did.
If you really want to jump through these kinds of hoops to make this work, then you could handle the grid's ControlAdded event and hook the LostFocus event of the child controls that are added to the grid. You would, of course, also want to unhook the event in ControlRemoved. But this isn't going to work very well for that you want, either, because the TextBox will lose focus when you leave one grid cell and move to another one, for example. In such a case, the TextBox loses focus and the grid gets focus.
This complexity with child control is why it's not a good idea to rely on GotFocus and LostFocus in DotNet for WinForms. The Enter and Leave events take care of all the child controls for you so you don't have to worry about it. Of course, they only fire when another control actually takes focus, and as we've already covered, the Toolbar buttons don't.
So after all this, we are basically back where we started. The simplest and easiest way for you to solve this problem is to simply call UpdateData on the grid in the click event of your toolbar button.
If the toolbar button does not gain focus, why then is the GotFocus event thrown when the toolbar button is clicked?
My guess is (and I say guess because we're really talking about the DotNet Framework here and not the Infragistics controls any more) that since the Toolbar is a separate windows and the GotFocus and LostFocus are tied to windows messages that as far as Windows is concerned, the toolbar gets focus. But that's not the same kind of focus we're talking about when we talk about focus in DotNet. Which is why, once again, Microsoft's documentation recommends using Leave and Enter and not using GotFocus and LostFocus.
Okay so the real confusion then is the word "focus" and even though a form of "focus" is placed on the button, it is not the type that is necessary to throw the Leave event. Would you agree?
Well, thank you for your time and help.
I think that's correct, yes. It would certainly explain all of the behaviors you are getting.