What is another alternative to `TextChanged` event - vb.net

I am working in windows form and have a few textboxes on a form.
These textboxes from top to bottom are connected, so if the text changes in textbox1, then txtbox2 and txtbox3 have to comply, if something changes in textbox2 then 3 has to comply;... and so on ... not going to bore you.
Now I was looking for an alternative, more efficient way of calling the textchanged event on the textboxes so it doesn't do everything everytime, even if one charater has changed....
Something like focus off textbox event ... or some other alternative .
This would be in vb.net and windows form.

You can use the TextBox.LostFocus event inherited from Control.LostFocus.
This event is fired when the control looses focus, like Tab or clicked on another control.

TextBox1.LostFocus perhaps? Or enable validation on the controls.
Control focus event order:
http://msdn.microsoft.com/en-gb/library/system.windows.forms.control.lostfocus.aspx
CausesValidation:
http://msdn.microsoft.com/en-gb/library/system.windows.forms.control.causesvalidation.aspx

Related

Opposite of SetFocus

MSAccess VBA:
Assume, in an arbitrary form, the focus is set to MyControl on that form.
How to "unset" the focus without giving the focus to another control?
I'm lokking for a code like
MyControl.UnsetFocus
In your circumstance, you probably want to just set focus back to the parent form. This meets the conditions of unsetting focus without giving another control focus, and tabbing or clicking will activate the focus / tab-navigation again from that form.
Here's an example:
Forms![MyForm].SetFocus
Note that per the documentation for SetFocus, if you attempt to SetFocus to a Form with child controls that have Enabled set, this will cause focus to automatically bounce to the first eligible child control per the documentation.
Form.SetFocus method (Access) # Microsoft Docs
The option to give focus to the parent form does work as proposed by meklarian
Alternatively, I recently had to do something similar but I wanted to update a textbox value and simply go back to whatever had focus before. This is another case where something like an "unsetfocus" would be awesome, but unfortunately doesn't exist.
Should you need to do something like this, the following works well
Screen.PreviousControl.SetFocus

Show on-screen keyboard when textbox clicked

I've built a on-screen keyboard for a surveillance system made in VBA. I need it so that when the user clicks on the textbox to enter the data, the on-screen keyboard I've made, shows up. Thanks!
Check out the _Enter() event that fires when a user clicks inside the textbox control.
Private Sub TextBox1_Enter()
frmKeyboard.Show
End Sub
For a more complete solution, you may want to wrap the keyboard showing/hiding events in a VBA class so you can more easily apply it to the different text boxes on your form. That way you don't have to repeat all of your code for each text box on your form. Just something to explore for down the road. :-)

Using combo boxes in Visual Basic

What is the best way to deal with a combo box event? In other words, what is the best event handler to use for the case that the user makes a selection from the combo box? I am using a textchanged event, but it seems a bit sloppy. Is there a better way? By the way, my program that I am using it for is a unit converter that converts length.
The textchanged event fires whenever the text inside the combobox changes. every character added to the combobox triggers it, which makes it sloppy.
To avoid performance issues, use either Lostfocus (which fires if the control isn't selected anymore) or the SelectedValue /Selectedindex changed events.
To answer your other question, manipulate the keypress event.
Go to the combobox's keypress event, and type this:
e.handled = true
this will reject any input from user.

How to use Button.KeyPress in vb

what I can do to execute Button.KeyPress event in vb ?
for example
Button.Click , should I press the button , so what about Button.KeyPress
Assuming you're talking about Runtime, in order to get the KeyPress event to fire, the Button needs to be first be selected, then press a (keyboard) button.
The KeyPress is normally used for things like a Textbox, it's not normally used with a Button
If you are looking for a way to force the Button.Click event, you can always call Me.Button1.PerformClick()

textchanged event of textbox in vb.net

I want to fire the textchanged event of textbox after the user enters text/data in the textbox in vb.net. But the event is getting fired as soon as the user enters the first word in the textbox.
is there any way I can solve this problem? I tried googling but didnt get satisfactory solution..
TextChanged Event is triggered when there is any change in the TextBox.
If you want to invoke something after user finishes up then try using LostFocus Event of the TextBox which will be triggered as user leaves the focus from textbox.