I have a pretty simple form that brings up a certain record when the "caseNumber" is selected from the combobox. Although after a selection is made within the combobox, it will freeze the entire form on the record selected. I can't click on any other text boxes or buttons. I have to stop the debugger. No errors are thrown. I've read where this has happened to others, but no answers to the problem, that I can find.
There is no code behind it so far, as the form is bound to a dataset and should just bring up the rest of the information once the caseNumber is selected.
Changed the "Selected Value" dropbox to "none" on the data binding menu for the combobox.
Under DataBindings, go to Advanced and make sure DataSource update mode is on NOne
A lot of times this happens because there is a problem in the binding. Are you sure it's not binding the text value of the control(the combobobox) to the data?
The correct way to bind (under DataBindings, Advanced) was to bind it to the SelectedValue instead of Text.
Please let us know a little bit more how your combobox is binded.
Related
I'm working on a fairly complex Access Database, trying to build forms with custom buttons for working with records. I'm using list boxes to display and navigate through records and all fields for existing records are disabled unless the user presses an edit button. The problem I'm having is that if I press the Edit or Add New button, enabling all of the fields, and then try to change the selection in a combo box, it does not update on the first try.
If I edit a text box first then the combo boxes work fine.
I've determined that the control's beforeUpdate and afterUpdate events are not firing on the first try but the action triggers the form_Dirty event and then it works as expected. I tried setting Me.Dirty = True with the Edit button and that solved the problem but it causes problems with some of my other code and it seems like an unnecessary workaround if only I understood the actual cause of the problem. It also works as expected if I leave the Combo Box unbound, but I am trying to build a template that doesn't require too much work to build new forms off of and I would rather not go that route.
It must have something to do with some bit of code I'm using because I can start a basic form and the combo boxes work fine.
I've started a basic test form and am adding code from my template form bit by bit until the problem arises, but it's a tedious process. Any help would be appreciated.
What am I missing? Is there some way of getting the Combo Box events to fire before the form is dirty?
UPDATE:
I have templates for a basic form, a form with a single subform, and a form with multiple subs in a tab control.
After some more testing I discovered that this problem does not apply to the basic form which has no subforms. This template uses similar code to the others for new, edit, cancel, save and delete buttons and for preventing accidental changes, preventing Form_unload during an edit and so on. The main difference I can think of off the top of my head is that the templates with subforms use class modules and collections to hold various data and pass it between the main form and subforms. Not sure if or how this might relate to combo box functionality.
I built most of this last winter then got too busy over the summer to work on it. Just now picking it up again and I'm having to re-learn a lot of the details of how my code works.
you can try to use Me.CboName.Requery in your After Update event.
I figured it out. I was calling a procedure with a form refresh in it from the Form_Dirty event and for whatever reason the refresh at exactly the wrong time was causing the combo box Before_Update and After_Update events to be skipped and the combo box value to not change. It was also causing text entered into a textbox to overwrite existing text on the first keystroke.
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
I have searched several forums but did not find answer for checking whether ComboBox is already DroppedDown via VBA code.
I have other code on Form_KeyDown events due to which anytime I press vbKeyDown it moves to next record. I need to check if ComboBox is DroppedDown then don't use other code and instead treat the default functionality of access where vbKeyDown will start scrolling through the items of ComboBox displayed in DropDown.
There is no such property, neither an event for OnDropDown or similar.
If the combobox has focus, you can force a dropdown using the DropDown method, but that's as close you can get.
I have a strange problem with a DataGridView I'm using which is bound to a table in VB.net
I've added a checkbox column to allow a user to tick a bunch of rows that I can then loop through and save off to a different table. All the checkboxes are enabled by default. So it's really a case of unchecking the rows which aren't required.
However, the DataGridView re-enables any checkbox that I click after I click on a checkbox in another row. So in effect, only one row can be unchecked at a time.
I'm sure I'm probably missing something obvious here?
EDIT: I forgot to mention this is a Windows form, not an ASP.net application.
I think this is what is happening. Please check if you have checked IsPostback while binding the datagridview. I think the click event of the checkbox is initiating a postback and it is rebinding itself.
HTH
I think the grid is refreshing and then redrawing the default values...
I got it working in the end, although I'm not sure exactly how. It must have been some property that I tweaked in the grid
I am creating a web control in vb.net that contains a list box. I know that I am able to choose a selection mode of Single or Multiple, but I am interested in limiting a Multiple selection to a predetermined size. For example preventing a user from selecting more than 3 items.
I have tried adding a Validator to the list box, which might be a way forward, but was wondering if there was a way of changing the selection mode to something a bit different than just the two specified ones.
Any ideas or suggestions would be greatly appreciated
Edit: Unfortunately due to project limitations I am unable to use Javascript on this problem. very annoying I know!
You could try handling one of the SelectedIndexChange events. With multiple selection, each time this event fires you can check how many items have already been selected. If it is more than you want, have the handler deselect the one that was just selected. You could also put up a little red label under the listbox saying "Sorry, no more than [n] selections allowed."
EDIT:
Just noticed you said WEB. Same theory applies, but it would have to be done using Javascript.
On the SelectedIndexChanged event, write a short piece of code that will check the number of selected items and if it is greater than your desired amount, unselect the new selection (or unselect the oldest one, or however you wish this to operate).