How do I create a new form instance whose name I have in a string? [duplicate] - vba

Code to create new form instance of a closed form using form name
I want to replace the long Select Case list with a variable.
Full code of module
In Access 2010 I have a VBA function that opens a new instance of a form when given a string containing the form's name. By adding a form variable "frm" to a collection:
mcolFormInstances.Add Item:=frm, Key:=CStr(frm.Hwnd)
The only way I can figure out to open "frm" is with a Select Case statement that I've manually entered.
Select Case strFormName
Case "frmCustomer"
Set frm = New Form_frmCustomer
Case "frmProduct"
Set frm = New Form_frmProduct
... etc ... !
End Select
I want it to do it automatically, somewhat like this (although this doesn't work):
Set frm = New Eval("Form_" & strFormName)
Or through some code:
For Each obj In CurrentProject.AllForms 'or AllModules, neither work
If obj.Name = strFormName Then
Set FormObject = obj.AccessClassObject 'or something
End If
Next
Set frm = New FormObject
I just want to avoid listing out every single form in my project and having to keep the list updated as new forms are added.

I've also done some testing of my own and some reading online about this. As near as I can tell, it isn't possible to create a new form object and set it to an instance of an existing form using a string that represents the name of that form without using DoCmd.OpenForm.
In other words, unless someone else can prove me wrong, what you are trying to do cannot be done.

I think you are looking for something like this MS-Access 2010 function. (The GetForm sub is just for testing):
Function SelectForm(ByVal FormName As String, ByRef FormExists As Boolean) As Form
For Each f In Application.Forms
If f.Name = FormName Then
Set SelectForm = f
FormExists = True
Exit Function
End If
Next
FormExists = False
End Function
Sub GetForm(ByVal FormName As String)
Dim f As New Form
Dim FormExists As Boolean
Set f = SelectForm(FormName, FormExists)
If FormExists Then
MsgBox ("Form Found: " & f.Caption)
Else
MsgBox ("Form '" & FormName & "' not found.")
End If
End Sub

Here's an ugly hack I found:
DoCmd.SelectObject <acObjectType>, <YourObjectsName>, True
DoCmd.RunCommand acCmdNewObjectForm
The RunCommand step doesn't give you programmatic control of the object, you'll have to Dim a Form variable and Set using Forms.Item(). I usually close the form after DoCmd.RunCommand, then DoCmd.Rename with something useful (my users don't like Form1, Form2, etc.).
Hope that helps.

Related

Access VBA - How to get the properties of a parent subform, or, get the user-given name for a subform (not the object reference name)

In MS Access 2016, let's say I have 2 forms: frmMain and frmBaby.
I have embedded frmBaby as a subform on frmMain. I have embedded on frmBaby a control (let's say it's a textbox, but it could be any control) named tbxInput.
On frmMain, since frmBaby is a "control" on frmMain, I have given that control the traditional name of subfrmBaby.
Now, in VBA, an event on subfrmBaby passes the tbxInput control ByRef (as Me.tbxInput) to a function that is meant to return the .Left property of the parent of the control passed ByRef. That is, I need the function to determine the .Left property for the location of subfrmBaby on frmMain. (The function is more complicated than this, but for the sake of keeping this question let's just say the function is returning the .Left property value because the .Left value is what I need to perform the function.)
Let's say the function is: Public Function fncLocation(ByRef whtControl As Variant) as Long
(I use Variant so that null values can be passed.)
Here is the code that I expected to return the .Left value of the parent (i.e., subfrmBaby) of whtControl: lngLeft = whtControl.Parent.Left
However, that gives me an error of: "Application or object-defined error"
When I use the immediate window to check things out I find that whtControl.Parent.Name is "frmBaby" and not "subfrmBaby" which makes it problematic to reference the subform on frmMain since I cannot figure out how to get the actual name given to the control on frmMain from the object passed to the function and so I cannot reference the subform by name either.
Questions:
How can I get the .Left value for the parent of the control passed to this function?
How can I get the actual name assigned to the subform control on frmMain? In this case, I need the name of "subfrmBaby" rather than "frmBaby."
Thanks in advance for ideas.
You can do this by iterating the controls on the main form, assuming whtControl is the form object of the subform (if it's a textbox, it's whtControl.Parent.Parent and If c.Form Is whtControl.Parent Then)
Dim mainForm As Form
Set mainForm = whtControl.Parent
Dim c As Access.Control
Dim subformControl As Access.Control
For Each c In mainForm.Controls
If TypeOf c Is SubForm Then
If c.Form Is whtControl Then
Set subformControl = c
Exit For
End If
End If
Next
If Not subformControl Is Nothing Then
Debug.Print subformControl.Left
End If
Note that iterating controls comes at a performance penalty, but this code should still take milliseconds, not seconds. Also, since we test reference equality, it works even if the same subform is present multiple times on the parent form.
I just had this issue, and I think I solved it! Thanks to Eric A's answer above to get me started. I tweaked it and built on it for my use. In my case, I needed to save the "full" address of a control to build and facilitate a control log (used to log both user actions for auditing and to allow for users to "undo" an action). I have several duplicated subforms in several sub-form controls, and a few sub-sub forms (each displaying differently filtered and sorted data), so I couldn't rely on simply knowing the subform's name, I also needed the subform control name. This also leverages others' work (as noted in the code notes with some tweaks to allow easier re-use for us. I've posted it here, hopefully it will help someone else. I know I've used SO a lot.
How we use it:
On a form, after logging an action, we record the control's ID info, which calls a function to get the toppost form (this is used in conjunction with afterUpdate event so we refresh the main form and subform). We also use the HWND to validate some other items elsewhere, and to grab a form if we don't have the initial form reference. If you use this and modify it, please point back to here and give comments.
Specific Function Code to get Control "address" and get control from address
' Posted on StackOverflow 2022 February 18 in response to Question:
' https://stackoverflow.com/q/66425195/16107370
' Link to specific answer: https://stackoverflow.com/a/71176443/16107370
' Use is granted for reuse, modification, and sharing with others
' so long as reference to the original source is maintained and you
' help lift others up as others have done those who helped with this concept
' and code.
Private Function GetControlAddress(ByRef ControlTarget As Object, _
ByRef ParentForm As Access.Form) As String
' Used in concert with building a form ID, this allows reflection back to the specific
' subform control and containing subform.
Dim ControlSeek As Access.Control
If TypeOf ControlTarget Is Form Then
' You need to dig through the whole list to get the specific controls for proper reflection down.
For Each ControlSeek In ParentForm.Controls
If ControlSeek Is ControlTarget Then
GetControlAddress = ParentForm.Name & FormIDHWNDSep & ParentForm.Hwnd & FormIDHWNDSep & ControlTarget.Name & FormIDFormSep
Exit For
ElseIf TypeOf ControlSeek Is SubForm Then
If ControlSeek.Form Is ControlTarget Then
GetControlAddress = ParentForm.Name & FormIDHWNDSep & ParentForm.Hwnd & FormIDHWNDSep & ControlSeek.Name & FormIDFormSep
End If
End If
Next ControlSeek
Else
' If you're not looking for a form, then you can skip the slow step of running through all controls.
GetControlAddress = ParentForm.Name & FormIDHWNDSep & ParentForm.Hwnd & FormIDHWNDSep & ControlTarget.Name & FormIDFormSep
End If
End Function
Public Function GetControlByAddress(ByRef StartingForm As Access.Form, ByRef strControlAddress As String) As Access.Control
' Given a control address and a starting form, this will return that control's form.
Dim ControlTarget As Access.Control
Dim TargetForm As Access.Form ' This is a reference to the hosting control
'Dim ControlSeek As
Dim FormIDArr() As String
Dim FormInfo() As String
Dim ControlDepth As Long
Dim CurrentDepth As Long
If strControlAddress = vbNullString Then GoTo Exit_Here
FormIDArr = Split(strControlAddress, FormIDFormSep)
' Because there's always a trailing closing mark (easier to handle buidling address), we skip the last array
' value, as it's always (or supposed to be...) empty.
ControlDepth = UBound(FormIDArr) - LBound(FormIDArr)
' Split out the form's Specific Information to use the details.
FormInfo = Split(FormIDArr(CurrentDepth), FormIDHWNDSep)
' The specific control is located in the 3rd element, zero referenced, so 2.
Set ControlTarget = StartingForm.Controls(FormInfo(2))
' If ControlDepth is 1 (control is on passed form) you can skip the hard and slow work of digging.
If ControlDepth > 1 Then
For CurrentDepth = 1 To ControlDepth - 1
' Note: you start at 1 because you already did the first one above.
' Split out the form's Specific Information to use the details.
FormInfo = Split(FormIDArr(CurrentDepth), FormIDHWNDSep)
Set TargetForm = ControlTarget.Form
Set ControlTarget = TargetForm.Controls(FormInfo(2))
Next CurrentDepth
End If
Exit_Here:
Set GetControlByAddress = ControlTarget
End Function
Required Helper Functions
Note, I use a property for the separators as there is some user locale handling (no included), and it also ensures that if we do change the separator it remains consistent. In this example, I simply set them to a character which is unlikely to be used in a form name. You will need to ensure your forms don't use the separator characters.
Public Function hasParent(ByRef p_form As Form) As Boolean
' Borrowed concept from https://nolongerset.com/get-top-form-by-control/
' and modified for our uses.
On Error Resume Next
hasParent = (Not p_form.Parent Is Nothing)
Err.Clear ' The last line of this will cause an error. Clear it so it goes away.
End Function
Private Function GetFormObjectByCtl(ByRef ctl As Object, _
ByRef ReturnTopForm As Boolean, Optional ByRef strControlAddress As String) As Form
strControlAddress = GetControlAddress(ctl, ctl.Parent) & strControlAddress
If TypeOf ctl.Parent Is Form Then
If ReturnTopForm Then
If hasParent(ctl.Parent) Then
'Recursively call the function if this is a subform
' and we need the top form
Set GetFormObjectByCtl = GetFormObjectByCtl( _
ctl.Parent, ReturnTopForm, strControlAddress)
Exit Function
End If
End If
Set GetFormObjectByCtl = ctl.Parent
Else
'Recursively call the function until we reach the form
Set GetFormObjectByCtl = GetFormObjectByCtl( _
ctl.Parent, ReturnTopForm, strControlAddress)
End If
End Function
Public Function GetFormByCtl(ctl As Object, Optional ByRef strControlAddress As String) As Form
Set GetFormByCtl = GetFormObjectByCtl(ctl, False, strControlAddress)
End Function
Public Function GetTopFormByCtl(ctl As Object, Optional ByRef strControlAddress As String) As Form
Set GetTopFormByCtl = GetFormObjectByCtl(ctl, True, strControlAddress)
End Function
Public Property Get FormIDHWNDSep() As String
FormIDHWNDSep = "|"
End Property
Public Property Get FormIDFormSep() As String
FormIDFormSep = ";"
End Property
Interesting. I don't think you can.
As you have seen, the parent of whtControl is its form, frmBaby.
The parent of that one is frmMain. The subform control is not part of the object chain when "going up", only when going down.
If you always use the naming scheme as in the question, you could do something like this (air code):
strSubform = whtControl.Parent.Name
strSubformCtrl = "sub" & strSubform
Set ctlSubform = whtControl.Parent.Parent(strSubformCtrl)

Access 2013 - Save Value from Textbox and display again when form is opened after close

I want to save a value from textbox in a string for example and display it again when the form get's openend.
I have two textboxes PriceRangeOne and PriceRangeTwo .. The user enter here for example 20 and 40
The problem i have is that when the user switches between Form and Report the values in this textboxes are beeing deleted. How can i save them?
I tried adding a sourcecontrol to the fields but had name errors eventhough i used different names.
I tried adding this to on change and retrieve it in an onload
Dim eingabe As String = textBox1.Text or .Value
Still didn't worked. Does anyone know a way to do this?
Typically, the most efficient and reliable way to do this is to have some form auto-open when the database is opened. It could be a dashboard, or just some form with nothing else on it. Whatever you use, launch it when the database opens and then minimize it. Now you have a form that's always open, as long as the application is open. Add a couple of textboxes to this form/dashboard.
When you close your form referenced in this question, write the values of PriceRangeOne and PriceRangeTwo to the textboxes on the form I described above. Then, when you open a new form or report, you can reference the values in those textboxes. Since the form is always open, you can reference these values at any time from any form or report until you close your database.
Solved it with variables.
I declared global variables in my standart module
For example
Public PriceOne As Double
Public PriceTwo As Double
Than i did this in my form in Close() and Open():
Private Sub Form_Close()
PriceOne = Me.Field
PriceTwo = Me.FieldTwo
End Sub
Private Sub Form_Open(Cancel As Integer)
Me.Field = PriceOne
Me.FieldTwo = PriceTwo
End Sub
Works perfect!
Courtesy of How to save the last value of a textbox. | Access World Forums:
Private Sub Form_Close()
'Set the default value for textbox
DoCmd.SetWarnings False
DoCmd.RunSQL "UPDATE table SET table.field = [Forms]![FormName]![Textbox] " & vbCrLf & _
"WHERE (((table.ID)=1));"
DoCmd.SetWarnings True
End Sub
Private Sub Form_Load()
'Load the default value for textbox
Me.Textbox.Value = DLookup("[field]", "[table]", "[ID]=1")
End Sub

Update value in another form's textbox via VBA

Hopefully this makes sense. I'm frustrated that I cannot figure this out. I have a simple Access 2010 database. I have a simple form inside it that helps the user input some specific information. This data entry situation can occur on two other forms in the database. Rather than have two copies of the "helper" form where the VBA code has hard-coded control references, I wanted to make it more universal by passing the name of the form that calls it by using the openArgs parameter.
When the time comes to transfer the values BACK to the form that needs the information, the helper form attempts to do this like so:
Private Sub cmdOk_Click()
Dim theFormName As String
Dim theForm As Form
theFormName = Me.OpenArgs
Set theForm = Forms.Item(theFormName)
If Not IsNull(theForm.Name) Then
theForm.txtLongitude.Value = Me.lblLongitude.Caption
theForm.txtLatitude.Value = Me.lblLatitude.Caption
End If
DoCmd.Close acForm, Me.Name, acSaveNo
End Sub
The variable theForm is populated correctly and theForm.Name returns the correct name of the form so that part works fine. The problem is that theForm.<controlName>.Value does not. When I run the code, I get an
application-defined or object-defined error (Run-time Error 2465)
I've tried all sorts of permutations for the control reference from the current open form to a second open form but I cannot get the syntax right. I've tried:
theForm!txtLongitude.Value ("..can't find the field txtLongitude..")
theForm.Controls("txtLongitude").Value ("..cant find the field...")
I have two suggestions. If one works, let me know and I'll edit my answer to only include the one that works.
Try changing theForm.txtLongitude.Value = Me.lblLongitude.Caption
to Forms!theForm!txtLongitude.Value = Me!lblLongitutde.Caption and theForm.txtLatitude.Value = Me.lblLatitude.Caption to Forms!theForm!txtLatitude.Value = Me!lblLatitude.Caption
If you've already tried that or it doesn't work, try declaring variables and "pulling" the values out of one form before putting them in the other form. (Also make sure the data type of both are the same.)
Private Sub Command4_Click()
Dim theFormName As String
Dim theForm As Form
Dim txtLong As String
Dim txtLat As String
txtLong = Me.lblLongitude.Caption
txtLat = Me.lblLatitude.Caption
theFormName = Me.OpenArgs
Set theForm = Forms.Item(theFormName)
If Not IsNull(theForm.Name) Then
theForm.txtLongitude.Value = txtLong
theForm.txtLatitude.Value = txtLat
End If
DoCmd.Close acForm, Me.Name, acSaveNo
End Sub

Problems when calling a public sub

I'm facing a deadend When trying to call this sub :
Public Sub backblue(ByVal frm As Form, ByVal boxname As String)
For i = 1 To 3
CType(frm.Controls(boxname & i.ToString()), TextBox).BackColor = Color.LightBlue
Next
End Sub
with button click event :
Private Sub Button1_click and bla bla....
backblue(Me, "txb1_")
End Sub
Can anybody show me a suggestion to fix the code.
It throws "Object Referrence not set to an instance bla bla" error
For information the textbox names are :
txb1_1 , txb1_2 , txb1_3
(these are some of the many textboxes in the form that i want its bakcolor changed)
and these three textboxes are already created through designer, not from execution.
i did check the textboxes names and there's nothing wrong.
the form class is also public.
if they are the only textboxs on said form you can just loop through
For Each box as Textbox In frm.Controls
box.BackColor = Color.LightBlue
Next
This error will occur if you do not declare the Form class to be public.
Also, make sure the textbox names are really correct, although this will probably cause a different error.
If you create the textboxes during execution, make sure they are initialized with New and added to the form's Controls collection.
Try this....
Public Sub backblue(ByVal frm As Form, ByVal prefix As String)
For i = 1 To 3
Dim bxName as String = prefix & i.ToString()
Dim bx as TextBox = CType(frm.Controls(bxName), TextBox)
If bx Is Nothing Then
MsgBox("Unable to find text box " +bxName)
Dim mtch() As Control = frm.Controls.Find(bxName, true)
If mtch.Length> 0 then
bx = mtch(0)
Else
Continue For
End if
End If
Bx.BackColor = Color.LightBlue
Next
End Sub
Although, a better solution would be to either create the textboxes inside a control and pass that control to BackBlue or to create an collection that has the controls and pass that in. Which brings up what is most likely yor problem your control is contained in a sub component and thus is not in the main form control collection
Alternative, you could use either the tag of the control or create a component control that implements IExtenderProvider and add it to the form --all of the above would effectively allow you to define the controls and/how they should be handled at designtime.
It may really seem that the names generated by this loop may not be the names of the original textboxes. My suggestion is before setting this Color property verify that the names generated by this loop are indeed the actual names. Maybe output this in a messagebox:
MessageBox.Show(boxname & i.ToString()) for each loop before you set the property

refer to name with variable in visual studio 2010 vb

I'm trying to assign text from "comp" in the form "home" to a textbox with the name "d1" in the form "home".
but this needs to be done with a counter in the form "home".
The code is in a module.
What I've tried=
home.controls("d" & home.counter).text = home.comp.text
I keep getting an error:
use the new keyword to create an object instance ==> the textbox exists in the form
check to determine if the object is null before calling the method ==> the textbox is empty
get general help for this exception
You could use Controls.Find:
Dim controls = home.Controls.Find("d" & home.counter, True)
If controls.Length > 0 Then
Dim txt = TryCast(controls(0), TextBoxBase)
If txt IsNot Nothing Then
txt.Text = home.comp.text
End If
End If
However, normally i would not use this approach since it's error-prone. Why don't you provide a public property in the Home-form that you can access? This property would get/set the TextBox' Text.
For example:
Public Property HomeCompText As String
Get
Return txtHomeComp.Text
End Get
Set(value As String)
txtHomeComp.Text = value
End Set
End Property
Now you can use this clear, safe and maintainable code:
home.HomeCompText = home.comp.text
You could even change the underlying control.