I'm new to VB (using VBA, actually) and I would like to force an event to fire. Specifically, I am updating the value in a textbox and I would like to call that textbox's AfterUpdate() event.
Private Sub cmdCreateInvoice_Click()
Me.txtInvDate = '11/01/10'
Me.txtInvDate.AfterUpdate
End Sub
During run time, I get an error that says "Compile Error: Invalid Use of Property". If I try something similar, but with the click event (ex: cmdCreateInvoice.Click), which does NOT have a property that shares the name, I get an error that says "Compile Error: Method or Data member not found".
I know there must be a way to fire one event from another. But what is the proper syntax?
Thanks!
AFAIK, there is no way to "fire an event manually" in VB(A). What you can do is call the event handler manually, and for this, rdkleine has given you the answer already:
Call txtInvDate_AfterUpdate()
This will have exactly the same effect as if the event had fired (though it does not give you the whole chain of events that may also fire along with it--unless you Call their handlers as well).
IgorM has another valid point, in comments on his answer--it's "cleaner" to write a different Sub to do the work you want done, then call it from both the event handler & wherever you're trying to do it now (button click?). So:
Private Sub txtInvDate_AfterUpdate()
DoWhatever
End Sub
Private Sub button_Click()
DoWhatever
End Sub
Private Sub DoWhatever
'your desired effect
End Sub
You could even make DoWhatever a Public Sub in a Module.
Edit
And no, in VB(A) it doesn't matter what order you define your Sub (or Function) routines.
Call
txtInvDate_AfterUpdate()
Try to use something like this:
Private Sub TextBox1_LostFocus()
TextBox1.Value = "5"
End Sub
Use LostFocus event if you change value manually.
Or you can use another way:
Private Sub CommandButton1_Click()
TextBox1.Value = "new value"
End Sub
Private Sub TextBox1_Change()
MsgBox TextBox1.Value
End Sub
Try to use Change event.
Some code apparently will (regretfully) force events to fire:
Me.Dirty = False
forces BeforeUpdate and AfterUpdate to fire, as I understand it. There are probably more cases too. Any secret hooks which attach to your code in that manner reflect bad design in my view and will inevitably lead to inadvertant & frustrating loops being created.
Is there a way to keep a textboxes event firing until I click on another text box? I'm needing to stay "in" the text box which has Do While loop for a selection. Once the selection is made, I want the user to be able to replace the selection without having to click on the text box again. If the user is satisfied with the select, they can click on a different text box.
Related
I have a bunch of TextBox-Button pairs on a form. When the button is clicked I want to insert the value of the text box into a database. The name TextBoxes and Buttons follow a naming standard, for example Value1Tb - Value1Cmd and Value2Tb - Value2Cmd.
My problem is that since I want to do the same for every button I would like the possibility to write a Sub like:
Private Sub AnyButton_Click(sender As CommandButton)
Dim tb As TextBox
Set tb = GetTBByName(s.Name)
PutValueToDatabase(s.Name,tb.Text)
End Sub
But I cannot find a way to point the Click-event of a Button to a different sub than the standard Name_Click().
Anybody know a way around this, that doesn't involve me writing 50 or so different Name_Click() subs?
If you are OK to use Form Controls rather that ActiveX, as it looks as though you may be at the moment, then Chris' solution seems good.
However if you need ActiveX CommandButtons then you are unable (as the VBA compiler will tell you, "Procedure declaration does not match...") to have parameters in the callback for the click event, and you are unable to raise the event from multiple objects, although you do of course know which button raised the event (since the relationship is 1 CommandButton = 1 Sub).
So... I would go with something like:
Private Sub Value1Cmd_Click()
Call TheMethod(Value1Cmd)
End Sub
Private Sub Value2Cmd_Click()
Call TheMethod(Value2Cmd)
End Sub
Private Sub TheRealMethod(sender As CommandButton)
' Do your thing '
Dim tb As TextBox
Set tb = GetTBByName(s.Name)
PutValueToDatabase(s.Name,tb.Text)
' Etcetera... '
End Sub
Requires a stub for each button, so some copying and pasting to begin with, but then easy to maintain etcetera as all _Click event callbacks are pointing at the same method...
Edit:
E.g.
Sub AutoWriteTheStubs()
Dim theStubs As String
Dim i As Long
For i = 1 To 10
theStubs = theStubs & "Private Sub Value" & CStr(i) & "Cmd_Click()" & vbCrLf _
& " Call TheMethod(Value" & CStr(i) & "Cmd)" & vbCrLf _
& "End Sub" & vbCrLf & vbCrLf
Next i
Debug.Print theStubs
End Sub
It seems that what you want is to get the name of the clicked button. If you are creating buttons like this:
(where 'i' increments in a loop)
Set btn = Sheet1.Buttons.Add( , , , ,)
With btn
.OnAction = "btnSub"
.Caption = "Upadate"
.Name = "btn" & CStr(i) & "Cmd"
End With
and then defining a generic "private sub btnSub()" for all the buttons, you could at least get the name of the button that was clicked using Application.Caller. Something like:
Private Sub btnSub()
Dim ButtonName As String
ButtonName = Application.Caller
MsgBox ("Hello:" & ButtonName)
End Sub
Hope it helps!
I decided to make this an answer because I am doing something similar and I confirmed that it works.
You can store the OLEobjects in a Collection, of arbitrary size, containing Custom Class Objects that include the OLEobjects and associations and the events that you need. Thus you can completely avoid any code stubs.
Create a Custom Class to bind the Button and TextBox pairs.
Declare the Button object WithEvents.
Include your call-back in the exposed button event handler in the Class Module.
Put a Public routine in a Standard Module to initialise a Collection of these Custom Class objects by spanning the Form Controls. You can also use this to Add the controls programmatically as a 'reBuild' option. The Collection can be inside another Class Module with all of the management routines, but it needs to be Instantiated and loaded in a Standard Module.
Put a public routine in a standard module to receive the call-backs with whatever context you need. This can also be in a Worksheet Module if it makes for better encapsulation. You can use late binding to reference the callback or CallByName.
You need to bear in mind that the Module of the Form will recompile every time you add a control, so you have to be careful where you put your code.
My application has the controls directly on the Worksheet Surface, so I can't put the the Collection Class in, or source any initialisation of the Collection from the Worksheet module. This would amount to self modifying code and it grinds excel to a halt.
I dreamed this idea up through bloody-minded idealism (not necessarily a good thing) but, of course, I was not the first one to think of it as you can see here. #Tim Williams explains it in his answer. You can also google VBA Control Array Events to see plenty of similar examples including an excellent article by #SiddharthRout. In line with the VB6 analogy, he uses an Array instead of a Collection to achieve the same result.
I'll try to post some code later. My application is a bit different so it will take a lot of work to trim it down, but the principle is the same.
The other thing to bear in mind is that VBE really struggles with this type of thing so don't worry if it is loading up you processors. After you re-start with VBE off, all will be fine.
I have this same situation, and I just have a click event for every button that is a wrapper to the function I want to call. This also allows you to pass sheet-specific parameters if you need to.
Example:
Public Sub StoreButton_Click()
' Store values for transaction sheet 3/27/09 ljr
Call StoreTransValues(ActiveSheet)
End Sub
I just published (Open Source) the Event Centralizer for MSForms.
Citation: "The Event Centralizer for MSForms is a VBA programming tool that allows all sorts of custom grouping when writing handlers for the events occurring in UserForms.
With the Event Centralizer for MSForms, it is easy for example to have all TextBoxes react the same way when the Enter event occurs, or all except one, or only those with a particular Tag value.
Thanks to its events logs system, the Event Centralizer for MSForms is a powerful learning and debugging help."
I can't explain here how it works. I tried to do it on the site.
Set the event to =FunctionName(parameter).
A bit late but this may help someone else:
If you have a function called OpenDocumentById(docID as integer), then each control calling the function would have in the event the following:
cmd1's On Click event:
=OpenDocumentById([DocID])
cmd2's On Click event:
=OpenDocumentById([DocID])
etc...
Consider a simple .NET form with a couple of radio buttons and a checkbox.
Each of the radio buttons has a CheckedChanged handler setup that performs some action based on the state of the checkbox.
My problem is, when I initialize on the default radiobutton to be checked (from the designer properties window) the CheckedChanged event is fired for that radio button, but the Checkbox hasn't been initialized yet so I either get a null pointer exception or the wrong value is used in the handler. Either way, I don't want that handler code to be run unless the user picks a radio button after the form has been loaded.
I currently get around this by not initializing the radio button, but I need to set that default eventually and the best place is from the designer. I also can add a boolean field that's not set to true until the form is fully loaded and not process the events if that is false, but it's a dirty hack.
What can I do to prevent that handler from running its code?
To make it feel slightly less dirty, if you initialize the controls in the constructor of the form you might be able to use the forms IsHandleCreated property rather than your own bool to check if it should actually validate or not.
I would think that normally you wouldn't want to validate anything before it's been shown for the first time and handle isn't created until it is.
Code Example:
Private Sub myRadioButton_CheckedChanged(sender As Object, e As EventArgs) Handles myRadioButton.CheckedChanged
If myRadioButton.Checked AndAlso myRadioButton.IsHandleCreated Then
'Do Work
End If
End Sub
"I also can put a boolean field that's not set to true until the form is fully loaded and not process the events if that is false, but it's a dirty hack."
It's also the easist and best way to do it!
Lets say .NET provides a neat way to turn an and off all the event handlers until the form is loaded. Even just the ones YOU are handling. It would still not be sufficiently flexible to disable what you wanted to enable but disable what you didn't. Often form setups happen and you want the events to fire. Also the form won't build right if no events fire.
The easy solution is to declare an initializing variable:
Private Initializing as boolean = True
Private Sub rb_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rbNuevos.CheckedChanged, RbDesaparecidos.CheckedChanged, RbModificados.CheckedChanged, RbNoDesap.CheckedChanged, RbDesHoy.CheckedChanged, RbChT.CheckedChanged
if Initializing then return
'Your Code
End Sub
Public Sub New()
' Llamada necesaria para el Diseñador de Windows Forms.
InitializeComponent()
' Agregue cualquier inicialización después de la llamada a InitializeComponent().
initializing = false
end sub
Most sophisticated: Remove the "handles" from the method, and use AddHandler on the new method.
Public Sub New()
' Llamada necesaria para el Diseñador de Windows Forms.
InitializeComponent()
' Agregue cualquier inicialización después de la llamada a InitializeComponent().
AddHandler RbChT.CheckedChanged, AddressOf rb_CheckedChanged
end sub
For radiobutton see Hans Olsson answer
For numeric up down, do it like this
Private Sub myNumeric_ValueChanged(sender As Object, e As EventArgs) Handles myNumeric.ValueChanged
If myNumeric.Value >= 0 AndAlso myNumeric.IsHandleCreated Then
'Do the work
End If
End Sub
The keyword is myNumeric.Value and IsHandleCreated
Yet another way:
Private Sub dgvGroups_CellValueChanged(sender As System.Object, e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgvGroups.CellValueChanged
If Me.Visible = False Then Exit Sub ' Sub gets called on form load which causes problems
wksGroups.Cells(e.RowIndex + 1, 1) = dgvGroups.Item(e.ColumnIndex, e.RowIndex).Value
wksGroups.Cells(1, 5) = dgvGroups.RowCount
One thing I've found that works is adding the events manually after you load the form.
To do this you can simply go into the generated form code found in the designer file of that form, and pull out the lines that add the event. It would look something like this:
this.controlName.CheckedChanged += new System.EventHandler(this.controlName_CheckedChanged);
Then put all of these calls into a method that you call after the InitializeComponent call in your form's constructor.
Just in case anyone is still searching for this the event is fired upon initializing the form BUT the form is not yet visible, Also Say that you have a foreign key relationship upon which you have a default value needed issue that gets fired every row update too. So the following code worked for me....
if (Visible && !(e.ColumnIndex == 0))
{
phoneEdited = true;
MessageBox.Show("A Phone entry has been entered");
}
Don't set checked on a control that really does much in designer.
The global flag and conditional exits where needed.
Try..Catch the sore spots to ignore a meaningless exception.
(Using VS 2017) It appears to me that it is an annoyance but not a bug. It is consistent with the model in use. The event is fired by normal operation of code, but code I did not write (but can access where fools fear to tread) and where there appears to be no (decent) place earlier in the normal flow to anticipate it.
The cleanest answer seems to be not to check radio button or checkbox controls in the designer at all if they trigger any significant code. Instead these controls should be changed by code (e.g. checked = true) in the Load event (for example) AFTER all the initialization is done.
There is no loss of flexibility here since both are fixed before the build, only in different places. The event handlers will handle it exactly as if a user had clicked the control in the natural flow of a well designed GUI application. (This reminds me of the ancient RPG proverb "Don't buck the cycle". (Anyone here remember RPG? I, not part of IBM-oriented team, never used it but had interesting discussions with some who did. ) Pre-checking controls hits the wrong part of the VS cycle.)
If for any reason that will not work, the next best thing is the kludge suggested elsewhere of a single status boolean initialized false and set true at the appropriate time with conditional exits in the necessary places to prevent them from crashing until then. It will get the job done, but it's ugly. Better than failure.
Another thing I tried before I decided that designer level pre-set checks were the problem and there was a very acceptable alternative was to put the danger spots in a Try..Catch to be able to ignore the exception. Also a kludge.
For the cleanest code, reverse the True/False approach used in some other examples. Focus on 'ready' rather than 'busy'. Here's an example for a Windows Form:
At the Class level, add Private app_ready As Boolean (it will be False by default).
At the end of the Form.Shown event handler, add app_ready = True.
In each control event handler where it's needed, add:
If app_ready Then
' code
End If
Starting a routine with something like If initialising Then Exit Sub just doesn't feel right!
Maybe for some functionality you can use the click event instead of the check changed event.
I put a public variable in the Module1 file
Dim Public bolForm_LoadingTF as Boolean = True
In each formLoad event I put
bolForm_LoadingTF = True
In each control with an OnSelectedIndexChanged
event I put if bolForm_LoadingTF = True then Exit Sub
At the end of the form load event I put
bolForm_LoadingTF = False
I am probably breaking a bunch of rules but this works
for me.
I'm looking to call a pre-existing event handler subroutine from the form_Load event handler.
But the below doesn't work because control doesn't come back and I want to do more.
UPDATE:
I'm new to this so I don't know what the proper protocol is but...
The reason for the non-return was that a statement like the below ended the subroutines execution.
If aLabel.Tag = 1...
the fix was adding New to the declaration to create an instance of it, ie..
changing....
Dim aLabel As Label
... to ...
Dim aLabel As New Label
I'm surprised I didn't get a warning but instead they just abruptly stopped execution of the sub. That wasn't very helpful :)
Thanks again for your time guys...
(Maybe this question should be deleted now that it has served its purpose)
#konrad #karl
END OF UPDATE
What doesn't work is....
Private Sub Form1_Load...
button1_Click(sender, e) 'But Control doesn't come back.
end sub
Do I change the sender to something?
Thanks in advance
Dave
Invoking event handlers like this is a bad idea, because you are trying to simulate the event context by making sender and/or EventArgs be something else.
Instead, put the logic that you want to invoke into a Subroutine or Function and have your Form1_Load method call that; likewise if you really do have a real click event handler, then that handler code can call the method too, like this:
Private Sub Form1_Load()
DoSomeWork()
End Sub
Protected Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs)
DoSomeWork()
End Sub
Private Sub DoSomeWork()
' Put logic here that you want to do from form load and a button click
End Sub
This has the benefit of making the code cleaner, clearer and easier to maintain as you only need to change the logic in one place should you need to change the logic.
Note: Obviously, you can pass parameters to the DoSomeWork method, if need be, and change it to a Function if you need it to return something.
I have a VBA (Excel 2010) system which involves selecting an item from a listbox and then displaying it in another form. Here is a very simplified version of what happens.
' Part of frmForm1 code module
sub lstListbox_Click
dim MyEvent as string
dim i as integer
i=me.lstListbox.listindex
MyEvent=me.lstlistbox.list(i)
' Now show the item in the second form
Load frmForm2
me.hide
ThisWorkbook.LoadDataIntoForm2 (frmForm2, MyEvent)
frmForm2.show
unload frmForm2
me.show
end sub
The listbox accepts the click, and first the event (the event handler is giver above). Key parts of the event handler are:
Load the second form (to display the detail data)
Pass the second form as a UserForm parameter to a procedure (LoadDataIntoForm2)
Hide the host form (frmForm1) and show the second form (frmForm2)
When the second form processes an Exit click, the code looks like this:
' Part of frmForm2 code module
sub cmdExit_Click
me.hide
end sub
The first time round it works fine - but when I return to frmForm1 (in the tail end of the lstListBox_Click procedure), even though the rest of the form is operative, the listbox remains stubbornly unresponsive.
I've managed to abstract this down to a little demo system if that would help - the same behavior is seen there. (It's regular .xls file, but that seems not to be easily acceptable as an upload)
Has anyone seen this before? And does anyone have any ideas how I might get this to work the way I want it to?
Thanks,
Tony
The default for the .Show method is to make the form modal. Explicitly set it to modeless:
Sub lstListbox_Click
...
Me.Show vbModeless
End Sub
m getting an error while using
Text1.SetFocus
the error is
invalid procedure call or argument
If you're calling this from a module, i.e. not from the form code, you need to reference the form object where text1 lays.
The other thing you may need to do is to get some persistency pills, hit F1 more often and use words in abundance when asking for help.
You need to reference Text1.SetFocus from Form_Activate and no from Form_Load -
http://www.vb6.us/tutorials/understanding-forms-vb6-tutorial
Form_Load vs. Form_Activate
In the Form_Load event, you would typically perform initialization-type tasks, as you should. However, certain types of actions cannot be performed in the Load event, due to the fact that the form is fully loaded only after the Load event completes. For one thing, printing to the form will not work when done in the Load event. In addition, if you try to set focus to a particular control on the form during the Load event, you will get the message Run-time error '5': Invalid procedure call or argument. For example, assume you had a textbox called Text1 on the form. The following code would result in that error:
Private Sub Form_Load()
' other initialization stuff
Text1.SetFocus ' causes an error
End Sub
The reason for the error is that since the form is not fully loaded, neither are any of the controls on it – and you can't set focus to a control that is not yet available.
To remedy this problem, you should use one of the other Form events, such as the Activate event. (When VB loads a form, it actually cycles through a number of events, such as: Initialize, Load, Resize, Activate, GotFocus, and Paint. Of these, Load and Activate are probably the ones most commonly used. ) Placing the code to set focus to a control will work in the Form_Activate event:
Private Sub Form_Activate()
' other statements
Text1.SetFocus ' no problem here
End Sub
A caution about the activate event: it will fire whenever your application switches to that form. For example, if you switch back and forth between Form1 and Form2, be aware that any code you might have in the Activate events for these forms will be executed when you switch to that form. Therefore, if you have code in the Activate event that you only want to execute "the first time", you will need to control execution with a Boolean switch. For example, in the General Declarations of your form you could define the following variable:
Private mblnFormActivated As Boolean ' will be initialized to False by default
You can then use this switch in the Activate event as follows:
Private Sub Form_Activate()
If mblnFormActivated Then Exit Sub
' statements you only want to execute once, including the following
' statement to turn the switch on:
mblnFormActivated = True
End Sub