I'm a bit confused here. I'm copying all the controls from one form to a panel on the main form and for some reason only about half of them copy.
Private Sub switchComponent()
Dim selection As String = TreeView1.SelectedNode.Text
Panel1.Controls.Clear()
Dim query = From cont In serverDic(selection).Controls
Select cont
For Each copier As Control In query
Panel1.Controls.Add(copier)
Next
End Sub
serverDic is defined as:
Dim serverDic As New Dictionary(Of String, frmServer)
When stepping through the code, serverDic(selection).Controls has 12 elements, but only 6 of them get copied. Next time this gets called, only 3 get copied. Does Panel1.Controls.clear() somehow kill the references?
EDIT: Just to show that there are infact 12 elements in the collection:
The problem here is that you are iterating over a collection that you are changing. When you add a Control to an container it is implicitly removed from it's previous parent and hence query. This is why you see exactly half of the items get removed.
With most collections this would be more apparent because they would throw if modified during an enumeration. The primary source of query here though is ControlCollection which does allow for modifications while enumerating.
To fix this problem just add the following line before the For Each loop.
query = query.ToList()
Related
I use a form that has controls that are dynamically added according to the class of object for which it is being used.
In order to load the next object into the form it is necessary to delete and rebuild the dynamic part.
I am experiencing random results when removing the objects using the code below, can you tell me where my error may be?
Sub CntrlKill(KillName As String)
For Each c In Me.Controls
If Strings.InStr(c.name, KillName) > 0 Then
Me.Controls.Remove(c)
End If
Next
End Sub
Translating the second link provided by GSerg to vb.net.
Create a list to hold the controls you want to delete. You can loop through the all the controls and add certain ones to a list. This does not effect the Controls collection. I haven't seen InStr used in a very long time. The .net .Contains will probably do what you need.
The second loop loops through the lstToDelete. This list is not effected by removing controls from the Controls collection.
The rule for For Each loops is don't effect the Collection you are looping through. You can change properties of the items in the collections. Just don't remove any items.
Sub CntrlKill(KillName As String)
Dim lstToDelete As New List(Of Control)
For Each c As Control In Controls
If c.Name.Contains(KillName) Then
lstToDelete.Add(c)
End If
Next
For Each c In lstToDelete
c.Dispose()
Next
End Sub
Or the backwards loop way.
Private Sub NukeControls(KillString As String)
For i = Controls.Count - 1 To 0 Step -1
If Controls(i).Name.Contains(KillString) Then
Controls(i).Dispose()
End If
Next
End Sub
I have a split Form in MS Access where users can select records in the datasheet and add it to a listbox in the Form thereby creating custom selection of records.
The procedure is based on a collection. A selected record gets transformed into a custom Object which gets added to the collection which in turn is used to populate the listbox. I have buttons to Add a Record, Remove a Record or Clear All which work fine.
However I thought, that pressing all these buttons is a bit tedious if you create a Selection of more then a dozen records, so i reckoned it should be simple to bind the actions of the Add and Remove buttons to the doubleclick event of a datasheet field and the listbox respectively.
Unfortunately i was mistaken as this broke the form. While a doubleclick on a field in the datasheet part of the form added the record to the listbox it was now unable to remove an item from the underlying collection giving me Run-time error 5: "Invalid procedure call or argument". Furthermore the clear all Button doesn't properly reset the collection anymore. When trying to Clear and adding a record of the previous selection the code returns my custom error that the record is already part of the selection and the listbox gets populated with the whole previous selection, which should be deleted. This leaves me to believe, that for some Reason the collection gets duplicated or something along these lines. Any hints into the underlying problem is apprecciated. Code as Follows:
Option Compare Database
Dim PersColl As New Collection
Private Sub AddPerson_Click()
AddPersToColl Me!ID
FillListbox
End Sub
Private Sub btnClear_Click()
Set PersColl = Nothing
lBoxSelection.RowSource = vbaNullString
End Sub
Private Sub btnRemovePers_Click()
PersColl.Remove CStr(lBoxSelection.Value)
FillListbox
End Sub
Private Sub FillListbox()
Dim Pers As Person
lBoxSelection.RowSource = vbaNullString
For Each Pers In PersColl
lBoxSelection.AddItem Pers.ID & ";" & Pers.FullName
Next Pers
lBoxSelection.Requery
End Sub
Private Function HasKey(coll As Collection, strKey As String) As Boolean
Dim var As Variant
On Error Resume Next
var = IsObject(coll(strKey))
HasKey = Not IsEmpty(var)
Err.Clear
End Function
Private Sub AddPersToColl(PersonId As Long)
Dim Pers As Person
Set Pers = New Person
Pers.ID = PersonId
If HasKey(PersColl, CStr(PersonId)) = False Then
PersColl.Add Item:=Pers, Key:=CStr(PersonId)
Else: MsgBox "Person Bereits ausgewählt"
End If
End Sub
This works alone, but Simply Adding this breaks it as described above.
Private Sub Nachname_DblClick(Cancel As Integer)
AddPersToColl Me!ID
FillListbox
End Sub
Further testing showed that its not working if i simply remove the Private Sub AddPerson_Click()
Edit1:
Clarification: I suspected that having 2 different events calling the same subs would somehow duplicate the collection in memory, therefore removing one event should work. This is however not the case. Having the subs called by a button_Click event works fine but having the same subs called by a double_click event prompts the behaviour described above. The issue seems therefore not in having the subs bound to more than one event, but rather by having them bound to the Double_Click event.
Edit2: I located the issue but I Haven't found a solution yet. Looks like Split-Forms are not really connected when it comes to the underlying vba code. DoubleClicking on the record in the datasheet view creates a Collection while using the buttons on the form part creates another one. When trying to remove a collection item by clicking a button on the form, it prompts an error because this collection is empty. However clicking the clear all button on the form part doesn't clear the collection associated with the datasheet part.
Putting the collection outside into a separate module might be a workaround but i would appreciate any suggestions which would let me keep the Code in the form module.
The behavior is caused by the split form which creates two separate collections for each one of its parts. Depending from where the event which manipulates the collection gets fired one or the other is affected. I suspect that the split form is in essence not a single form, but rather 2 instances of the same form-class.
A Solution is to Declare a collection in a separate module "Coll":
Option Compare Database
Dim mColl as new Collection
Public Function GetColl() as Collection
Set GetColl= mColl
End Function
And then remove the Declaration of the Collection in the SplitFormclass and Declare the Collection in every Function or Sub by referencing the collection in the separate Module like in the following example:
Option Compare Database
Private Sub AddPersToColl(PersonId As Long)
Dim Pers As Person
Dim PersColl as Collection
Set PersColl = Coll.GetColl
Set Pers = New Person
Pers.ID = PersonId
If HasKey(PersColl, CStr(PersonId)) = False Then
PersColl.Add Item:=Pers, Key:=CStr(PersonId)
Else: MsgBox "Person Bereits ausgewählt"
End If
End Sub
This forces the form to use the same Collection regardless if the event is fired from the form or datasheet part of the split-form. Any Further information is appreciated but the matter is solved for now.
Thanks everyone for their time
I'm trying to save the values of data that have been input into my form. There are a total of about 50 different fields to save across 5 different agents, so I loaded the data into arrays.
I've tried saving the fields in a loop, but it doesn't seem to work in a loop, only if each field has a separate line, which is a lot of code and messy. The Ag1Name, Ag2Name and Ag3Name are the names of my textboxes that the user enters to populate the form.
Sub LoadAndSaveData()
NumberofAgents = 3
Dim AgentName(3) as String
AgentName(1) = Ag1Name.Value
AgentName(2) = Ag2Name.Value
AgentName(3) = Ag3Name.Value
For Count = 1 To NumberOfAgents
With ActiveDocument.CustomDocumentProperties
.Add Name:="AgentName" & Count, LinkToContent:=False, Value:=AgentName(Count), Type:=msoPropertyTypeString
End With
Next Count
End Sub
The data doesn't get saved to the Custom Document Properties when the code is set up in a loop like the above. Since there are so many values to save and all the data is already in arrays, I would much prefer to use a loop rather than write out a separate line of code for all ~50 of the values. It does seem to work when each field is saved in a separate line of code.
I think this would probably get what you want. You don't really need to count the document properties first, only increment with the ones you want to update. Hopefully the only document properties you want contain the name AgentName in it.
ReDim AgentName(0) As String
Dim P As Long
For Each c In ThisDocument.CustomDocumentProperties
If InStr(1, c.Name, "AgentName", vbTextCompare) > 0 Then
ReDim Preserve AgentName(P)
AgentName(P) = c.Value
P = P + 1
End If
Next c
As a guest I cannot post a comment here, but the code you gave works OK here.
However, there is a problem with creating legacy custom document properties programmatically, because doing that does not mark the document as "changed". When you close the document, Word does not necessarily save it and you lose the Properties and their values.
However, if you actually open up the Custom Document Property dialog, Word does then mark the document as "changed" and the Properties are saved.
So it is possible that the difference between your two scenarios is not the code, but that in one scenario you have actually opened the dialog box to check the values before closing the document and in the other you have not.
If that is the case, here, I was able to change this behaviour by adding the line
ActiveDocument.Saved = False
after setting the property values.
If you do not actually need the values to be Document Properties, it might be better either to use Document Variables, which are slightly easier to use since you can add them and modify them with exactly the same code, or perhaps by storing them in A Custom XML Part, which is harder work but can be useful if you need to extract the values somewhere where Word is not available.
You can make this even easier by looping the controls on the UserForm, testing whether the control name contains "Ag" and, if it does, create the Custom Document Property with the control's value - all in one step.
For example, the following code sample loops the controls in the UserForm. It tests whether the controls Name starts with "Ag". If it does, the CustomDocumentProperty is added with that control's value.
Sub LoadAndSaveData()
Dim ctl As MSForms.control
Dim controlName As String
For Each ctl In Me.Controls
controlName = ctl.Name
If Left(controlName, 2) = "Ag" Then
With ActiveDocument.CustomDocumentProperties
.Add Name:=controlName, LinkToContent:=False, value:=ctl.value, Type:=msoPropertyTypeString
End With
End If
Next
End Sub
I feel a little stupid... I just realized that the reason that the code wasn't working was that the variable NumberofAgents was not being calculated correctly elsewhere in my code. I've got it working now. Thanks for your thoughts!
here is the situation:
I have defined a structure called "cell"
in this structure I have included textbox called "display"
my code is this:
Dim new_cell As New cell
new_cell.display.Multiline = True
there are no syntax or run-time "errors" but having put a breakpoint on the second line, when the program gets to it it stops running the sub and carries on as normal, can anybody explain what is the problem?
EDIT
cell definition:
Structure cell
Dim candidates As List(Of Integer)
Dim constraints As List(Of Integer)
Dim x As Integer
Dim y As Integer
Dim display As TextBox
End Structure
As suggested, the second line of your first code snippet will throw a NullReferenceException. If that code is in the Load event handler of a form then, on 64-bit systems, the exception will just be swallowed and the only notification will be in the Output window.
If you want a TextBox then you have to create a TextBox. Where that TextBox gets created depends on what you're trying to achieve. Regardless, that type should be a class rather than a structure. You should also think about using properties rather than public fields and you also ought to think about starting appropriate names with an upper-case letter.
I have been playing around with some code, and I have made easily 50+ controls that all are labeled: PictureBox[XCoordinate]_[YCorrdinate] (Replacing the brackets and contents with the coordinates of them on a little grid I made.)
The problem with this is it is a real pain to use a control when doing loops to update all the picture boxes. I want to know how to do code like:
'This code assumes that the picture boxes are all initialized.
Dim XCoordiante As Integer = 5
Dim YCorrdinate As Integer = 2
PictureBox[XCoordinate]_[YCoordiante].Image = [Put Image Here]
I am going to put this within a loop. Is there a way that I can do this without manually typing it all and risking missing something within a case statement? And also, I would have to retype it for every different kind of change I want to make (ex: tag or error image).
Would a pointer somehow help? I don't really know how to do this, but it would be really helpful if possible.
When you create them, save them to a List:
Private pList As New List(Of PictureBox)
Dim pic As New PictureBox
With Pic
.Location = ...
' etc
End With
Me.Controls.Add(pic)
pList.Add(pic)
Assuming they are created in some sort of order:
For n As integer = 0 To pList.Count = 1
' add code to look at Plist(n).X and .Y to determine what to do (?)
Plist(n).Image = ...
Next n
If there is more info to capture, create a custom class of a PicBox and the other info, and make the list a List(Of myPicClass).