Can dynamic variables be created in vb.net - vb.net

I'm trying to dynamically create variables if possible.
I have a list box containing check boxes. The user selects items from it and the selections are then added to a database. They can select any number of items from the list (1-7). I have iterated through the selected items and added them to an arraylist.
I now want to store each selected item in a different variable to be added to the database. The idea is to use just one insert statement which is expecting 7 entries. If the user only selects say 2 items, these are inserted as well as 5 empty strings.
Dim part1 As String = ""
Dim part2 As String = ""
Dim part3 As String = ""
Dim part4 As String = ""
Dim part5 As String = ""
Dim part6 As String = ""
Dim part7 As String = ""
'add selected items to an array
For i = 0 To listPart.CheckedItems.Count - 1
selected.Add(listPart.CheckedItems(i).Text)
Next
I'd like to do something like:
For j = 0 To selected.Count
part+j = selected(j)
Next
This way I should have variables holding empty strings if the user does not select all 7 items

I don't think dynamic variables can be created, or need to be created.
Objects like ArrayList, Array, List, and Collection support adding items ( similar to how you are describing adding dynamic variables)
If you are looking to add a database entry for each item in the listview it's possible you could just loop through the listview
For item as ListViewItem in listPart.Items
'Save item.Text
Next item

you can do this with reflection, but it is not advisable. It is hard to debug, it is hard to implement, and it can lead to issues down the road with access restrictions.
http://msdn.microsoft.com/en-us/library/6z33zd7h.aspx
System.Reflection.FieldInfo FI = T.GetField("part" & j);
FI.SetValue({your class name here},selected(j));

Related

How to reference similar named textboxes within a loop, with the loop iteration [duplicate]

So I have a table that has a list of totals im trying to display on a form, I have 10 totals I need to get from the totals table and display in 10 textboxes on the form.
The 10 textboxes are "A1, A2, A3..." and its using DLookup to find the ID field number.
It seems like its a syntax issue with Me.TEXTX & X1.Value though I'm not sure how else I can type it.
Hope this makes sense. Thanks!
Private Sub UPDATETOTALS()
Dim FORMX As String
FORMX = "GRID"
Dim TEXTX As String
TEXTX = "A"
Dim TABLENAMEx As String, FINDFIELDx As String, GETFIELDx As String
TABLENAMEx = "GRID_TOTALS"
FINDFIELDx = "[ID]="
GETFIELDx = "TODAY"
Dim X1 As Integer
For X1 = 1 To 10
Me.TEXTX & X1.Value = DLookup(GETFIELDx, TABLENAMEx, FINDFIELDx & X1)
Next X1
End Sub
You cannot access an object reference directly using a concatenated string, as such reference is not of string data type.
Instead, you will need to access the object from the relevant collection (in this case, the Controls collection), by supplying the name of the object (as a string) to the Item method of that collection.
Since the Item method is the default method for a collection, the item name can immediately follow the collection as an argument.
For example:
For X1 = 1 To 10
Me.Controls(TEXTX & X1).Value = DLookup(GETFIELDx, TABLENAMEx, FINDFIELDx & X1)
Next X1

Excel VBA - Return selected element in slicer

I have a slicer called 'Slicer_HeaderTitle'. I simply need to be able to dim a variable in VBA with the value of the selected element. I'll only have one element selected at a time.
I've had a lot of problems with selecting and de-selecting elements from my slicer dynamically via VBA, since my pivot table is connected to an external data-source. I don't know if this is relevant for this exact example, but this table is connected to the same external data-source.
I used to have a single line of code, which could return this value, but all i could find now requires you loop through each element in the slicer and check if it's selected or not. I hope to avoid this, since I only have 1 selected element at a time.
' This is what I'm trying to achieve.
Dim sValue as String
sValue = ActiveWorkbook.SlicerCaches("Slicer_HeaderTitle").VisibleSlicerItems.Value
msgbox(sValue)
'Returns: "Uge 14 - 2016 (3. Apr - 9. Apr)"
Current Status:
This is what i did:
Public Function GetSelectedSlicerItems(SlicerName As String) As String
Dim SL As SlicerCacheLevel
Dim sI As SlicerItem
Set SL = ActiveWorkbook.SlicerCaches(SlicerName).SlicerCacheLevels(1)
For Each sI In SL.SlicerItems
If sI.Selected = True Then
GetSelectedSlicerItems = (sI.Value)
End If
Next
End Function
Dim sValue As String
sValue = GetSelectedSlicerItems("Slicer_HeaderTitle")
Thanks to Doktor OSwaldo for helping me a lot!
Ok to find the error, we will take a step back, delete my function and try Looping through the items:
Dim sC As SlicerCache
Dim SL As SlicerCacheLevel
Dim sI As SlicerItem
Set sC = ActiveWorkbook.SlicerCaches("Slicer_Dates_Hie")
Set SL = sC.SlicerCacheLevels(1)
For Each sI In SL.SlicerItems
sC.VisibleSlicerItemsList = Array(sI.Name)
Next
I would like to put in my two cents. The set of visible slicer items may be shrunk by both independent actions:
User selection of items in slicer A. To capture those items, use .Selected method.
Selection of items in slicer B which in consequence shrinks the list of slicer A items. To capture those items, use .HasData method.
Note that you may see only say two items of Slicer_Products (apples, bananas) because some other slicer Slicer_Product_Type has active filter on fruits. The method sI.Selected would still return the whole list of products apples, bananas, carrots...
If you want both limitations to be in place then make intersection of both sets. I have modified TobiasKnudsen code (excellent answer!) to return the list of items shrunk by both above limitations. If sI.Selected = True And sI.HasData = True Then is the key line in this code.
Option Explicit
Sub TestExample()
Dim MyArr() As Variant
MyArr = ArrayListOfSelectedAndVisibleSlicerItems("Slicer_A")
'now variable MyArr keeps all items in an array
End Sub
Public Function ArrayListOfSelectedAndVisibleSlicerItems(MySlicerName As String) As Variant
'This function returns an array of the limited set of items in Slicer A
'Limitation is due to both:
'(1) direct selection of items by user in slicer A
'(2) selection of items in slicer B which in consequence limits the number of items in slicer A
Dim ShortList() As Variant
Dim i As Integer: i = 0 'for iterate
Dim sC As SlicerCache
Dim sI As SlicerItem 'for iterate
Set sC = ThisWorkbook.Application.ActiveWorkbook.SlicerCaches(MySlicerName)
For Each sI In sC.SlicerItems
If sI.Selected = True And sI.HasData = True Then 'Here is the condition!!!
'Debug.Print sI.Name
ReDim Preserve ShortList(i)
ShortList(i) = sI.Value
i = i + 1
End If
Next sI
ArrayListOfSelectedAndVisibleSlicerItems = ShortList
End Function
Sub Demo()
Dim i As Integer
With ActiveWorkbook.SlicerCaches("Slicer_Country")
For i = 1 To .SlicerItems.Count
If .SlicerItems(i).Selected Then
Sheets("Pivot Sheet").Range("I" & i) = SlicerSelections & " " & .SlicerItems(i).Value
End If
Next i
End With
End sub
This is how I managed to identify the selected element on a slicer.
The answer by TobiasKnudsen above did not work for me as I got an error stating the data source needed to be an OLAP source.
My data is an excel table and this is the code that worked:
Dim val as Boolean
val = ThisWorkbook.SlicerCaches("Slicer_MYSLICER").VisibleSlicerItems.Item("CS").HasData
In my case, the slicer had only 3 items so I repeated the line above with a different string in item()
So, where val was true, that was the item that was currently selected.

Speed up declaring variables?

I have a bunch of Variables I need to declare and was wondering if there's any way to shorten the amount of lines needed to do so. Here's the code:
Sub test()
dim comps as New Collection
dim noOfCompanies as Integer: noOfCompanies = 25
dim c1 as New Names 'Names is a class I have made
dim c2 as New Names
... ' in this gap is c3 to c29
dim c30 as New Names
End Sub
I don't know that you can create a variable and do something like the following, can you? (Note: Psuedocode)
dim i as Integer
for i = 1 to 30
Dim "c" & i as New Names
next i
edit:
#rene mentioned using an array - how would I do so, if later I'm going to set parts of the class properties (sorry, I'm learning classes and don't know the proper terms):
c1.companyCode = 10: c1.companyCountry = "USA": c1.companyName = "Batman LTD"
c2.companyCode = 13: c2.companyCountry = "Krypton": c2.companyName = "Superman LLC"
... 'etc until c30.
Here's what I'm trying so far, but to no avail:
Dim tempC As String, tempN As String
For i = 1 To noOfCompanies
c(i) = "c" & i
tempC = c(i)
Debug.Print tempC 'This will correctly print "c1", "c2", "c3", etc.
Dim c(i) As New Names 'This is where I can't figure out how to declare the different array parts as an individual "new Names" class part.
Debug.Print tempN
Next i
edit2:
Here's why I'm trying to create 30 variables. I get a spreadsheet every week that has a column of codes (the codes being that companyCode I am initializing above). If I find a row with any of the 30 codes I am trying to declare, then I need the companyName and companyCountry to be placed in some other cells on that row. My idea was to be able to just do something like this (psuedocode):
dim rng as Range
rng = Range("A1:A30") 'this has the codes in it, i.e. 13, 10, 11, 20...
for each cel in Rng
'here would be code where I just check for IF the cel.Value is anywhere in companyCode,
'return its equivalent companyCountry and companyName
next cel
So, would a dictionary be best? I could do like
if dict.exists(cel.value)
BUT how could I store the companyCountry and companyName in the same dictionary entry, AFAIK I can only store one key per entry?
...of course, if just saving this info in an excel table somewhere (xlsx or csv) and just opening/using that then closing would be best practice, just let me know!
Dim arrNames(1 to 30) as Names, n
for n=1 to 30
Set arrNames(n)=new Names
next n
arrNames(5).companyCountry = "USA"
EDIT: I think storing your code information on a worksheet and accessing it directly is the "best" approach unless you need high-volume/high-performance lookups (even then it will not be bad...)
For example here's a pretty simple function you can call from VBA:
Function CompanyInfo(companyCode, infoType As String)
Dim rng As Range, colNum As Long, rv
Select Case infoType
Case "Country": colNum = 2
Case "Name": colNum = 3
Case Else
CompanyInfo = "InfoType?"
Exit Function
End Select
rv = Application.VLookup(companyCode, _
ThisWorkbook.Sheets("Codes").Range("A2:C100"), _
colNum, False)
CompanyInfo = IIf(IsError(rv), "???", rv)
End Function
Usage:
Dim v, v2
v = CompanyInfo(10,"Country")
v2 = CompanyInfo(10,"Name")
Example using a collection to create 30 instances of a class containing the name.
If it is imperative that they be able to be retrieved using "c1-c30", then you can either use that as a variable in the class (like Name) or as the collection index/key.
For example:
Names Class:
Private pName As String
Private pOther As Integer
Public Property Get Name() As String
Name = pName
End Property
Public Property Let Name(Value As String)
pName = Value
End Property
Assigning and Printing our 30 Names:
Sub Test()
Dim MyNames As Collection
Set MyNames = New Collection
Dim x
For x = 1 To 30
Dim t As Names
Set t = New Names
t.Name = "c" & x
MyNames.Add t
Next x
Dim y
For Each y In MyNames
MsgBox (y.Name)
Next y
End Sub
In closing, I think your problem is that you want to be able to reference these 30 cnames in your code by name later after having assigned them. That's not going to work and it's a bad coding practice. You shouldn't do:
Dim c1
Set c1 = new Names
c1.Name = "Bob"
Dim c2 '...
There's a reason people don't typically declare 30 variables with incremental numbers. The reason is because there is a better way. That way is typically using a collection of variable types or an array of variable types that you can reference using an index or a loop.
If you're creating 30 instances of a certain data type, and you want to give them each unique values, create a table or even a static array to hold their values and assign them in a loop.
To follow up, if you want to reference them using c & x then add a variable to your class called ID and assign to that.
You might want to look into using a dictionary if you would like to be able to quickly retrieve the ID without looping through and checking ID's.
Edit:
I'm glad you explained your end game. You are absolutely over-complicating this scenario.
A simple VLOOKUP formula and a lookup table would save you from having to code anything in VBA at all.
Example:
Create a named range called LookupTable that contains the company ID's on the far left:
Then, use these formulas to search your table for the ID, and give you the name/location.
Parameter 1 is the value to Lookup
Parameter 2 is our LookupTable
Parameter 3 is the column from our table to return
(1 = ID, 2 = Company Name, 3 = City)
Parameter 4 says we want an exact match only.
=VLOOKUP(A1,LookupTable,2,FALSE)
I'm not sure if I like the use of "Names" as a class name since "Names" already has an Excel VBA meaning, but if that's what you want.
As others have pointed out, an array is probably the way to go. But if you really want to have 30 variables and you don't want to do a lot of typing, you can do something like this:
Sub DeclareVars()
Dim i As Long, v As Variant
ReDim v(1 To 30)
For i = 1 To 30
v(i) = "c" & i & " As New Names"
Next i
Debug.Print "Dim " & Join(v, ", ")
End Sub
Run it once and copy the result from the immediate window into your code. If you know Python you can use a 1-liner in the Python shell and type even less. Just evaluate:
"Dim " + ", ".join('c' + str(i) + " As New Names" for i in range(1,31))
Why don't you store your c1, ... c30 objects properties in a table, an xml file, a csv file, or any other of the multiple types of files? That can store data and be read via VBA.
So, when needed, you can just open the table, and populate an array of your object's properties with the values in the table? If your table/file contains 30 lines, an array of 30 objects will then be created.
By doing this, you will also separate your code from your data, which is usually considered as a best practise.

Using selected values in an Excel list box to formulate the legend

I am attempting to pass the selected values from a list box in Excel to legend in a chart. Specifically, I have data of certain companies in the following format
And I also have a list box, globalList, which contains the names of companies that can be selected. Selected companies' data will then be passed onto a chart using VBA.
However, the problems I encounter are in the following sections:
Initialising a variable to hold values selected in the globalList
listMax = globalList.ListCount - 1
`this creates the upper bound for the list box
For i = 0 To (globalList.ListCount - 1)
If globalList.Selected(i) = True Then
companiesSelected = companiesSelected + 1
End If
If i = listMax Then
Exit For
End If
Next i
`the above is used to retrieve the number of companies that have been selected by a user - whether =0 or > 0
Dim myLegend() As String
ReDim myLegend(0 To (globalList.ListCount - 1))
For i = 0 To (globalList.ListCount - 1)
If globalList.Selected(i) = True Then
myLegend(i) = globalList.List(i)
End If
If i = listMax Then
Exit For
End If
Next i
`this is the array object in which I intend to store company names selected in the list box.
The problem is that even though the above creates the myLegend string array, it also contains empty array items for the companies that may not have been selected by the user in the list box.
And even if I am able to remove these empty items from the array, the following problem occurs
Passing the held values from my variable to my chart
For i = 1 To companiesSelected
myChart.SeriesCollection(i).Name = myLegend(i)
Next i
Problem here is that myLegend array starts from 0, while SeriesCollection seems to start from 1. So I am unable to pass the string values for selected items to the legend of my chart's.
Could somebody please point out how to circumvent these problems?
Many thanks in advance!
Here is a code to extract the selected items into an one-based array of String (without empty items):
Dim i As Integer
Dim iCount As Integer
Dim myLegend() As String
iCount = 0
With globalList
ReDim myLegend(1 To .ListCount)
For i = 0 To .ListCount - 1
If .Selected(i) = True Then
iCount = iCount + 1
myLegend(iCount) = .List(i)
End If
Next i
End With
If iCount > 0 Then
ReDim Preserve myLegend(1 To iCount)
Else
ReDim myLegend(1 To 1)
myLegend(1) = "Nothing here!"
End If

Multi Select List Box

I have a list box on a form and it works fine for what I want to do.
I am wanting to edit items on the form, this means populating the listbox and then selecting the relevant items.
My listbox contains a list of item sizes, i want to select the sizes which belong to the item being edited.
PLease can someone give me some pointers.
I tried me.lstItemSizes.SetSelected(i,true) but this only works for a single item.
Any help wil be much appreciated.
My Code:
Private Sub SelectItemSizes(ByVal itemID As Integer)
Dim itemSizes As IList(Of ItemSize) = _sizeLogic.GetItemSizes(itemID)
Me.lstItemSizes.SelectionMode = SelectionMode.MultiExtended
If (itemSizes.Count > 0) Then
For i As Integer = 0 To Me.lstItemSizes.Items.Count - 1
For x As Integer = 0 To itemSizes.Count - 1
If (CType(Me.lstItemSizes.Items(i), PosSize).SizeID = itemSizes(x).SizeID) Then
Me.lstItemSizes.SetSelected(i, True)
Else
Me.lstItemSizes.SetSelected(i, False)
End If
Next
Next
End If
End Sub
Did you set the selectionmode to multi?
You need to specify that in order to allow multiple selections.
Then you can do:
Dim i as Integer=0
For i=0 To Me.listBox.SelectedItems.Count -1
'display the listbox value
next i
Here is a screen shot:
After you set the property on the listbox then call setselected based on the values you want selected.
me.lstItemSizes.SetSelected(3,true)
me.lstItemSizes.SetSelected(4,true)
me.lstItemSizes.SetSelected(9,true)
Here you can add 20 numbers and only select the even.
Dim i As Integer
'load the list with 20 numbers
For i = 0 To 20
Me.ListBox1.Items.Add(i)
Next
'now use setselected
'assume only even are selected
For i = 0 To 20
If i Mod 2 = 0 Then
Me.ListBox1.SetSelected(i, True)
End If
Next
3rd edit
Look at the way you are looping, lets assume I create a list of integers, my vb.net is rusty I mainly develop in C#. But assume you did this:
Dim l As New List(Of Integer)
l.Add(2)
l.Add(6)
l.Add(20)
You only have three items in your list, so first loop based on the items on your list, then within the items in your listbox, you have it vice versa. Look at this:
Dim i As Integer
Dim l As New List(Of Integer)
l.Add(2)
l.Add(6)
l.Add(20)
'load the list with 20 numbers
For i = 0 To 20
Me.ListBox1.Items.Add(i)
Next
Dim lCount As Integer = 0
For lCount = 0 To l.Count - 1
For i = 0 To 20
If i = l.Item(lCount) Then
Me.ListBox1.SetSelected(i, True)
Exit For
End If
Next
Next
In the code my l is a list of just 3 items: 2, 6, and 20.
I add these items to l which is just a list object.
So now I have to loop using these 3 numbers and compare with my listbox. You have it the opposite you are looping on your listbox and then taking into account the list object.
Notice in my for loop that once the item in my list is found I no longer need to loop so I exit for. This ensures I dont overdue the amount of looping required. Once the item is found get out and go back to the count of your list object count.
After running my code here is the result
You have to change the ListBox.SelectionMode property in order to enable multiple-selection.
The possible values are given by the SelectionMode enum, as follows:
None: No items can be selected
One: Only one item can be selected
MultiSimple: Multiple items can be selected
MultiExtended: Multiple items can be selected, and the user can use the Shift, Ctrl, and arrow keys to make selections
So, you simply need to add the following line to the code you already have:
' Change the selection mode (you could also use MultiExtended here)
lstItemSizes.SelectionMode = SelectionMode.MultiSimple;
' Select any items of your choice
lstItemSizes.SetSelected(1, True)
lstItemSizes.SetSelected(3, True)
lstItemSizes.SetSelected(8, True)
Alternatively, you can set the SelectionMode property at design time, instead of doing it with code.
According to MSDN, SetSelected() can be used to select multiple items. Simply repeat the call for each item that needs to be selected. This is the example they use:
' Select three items from the ListBox.
listBox1.SetSelected(1, True)
listBox1.SetSelected(3, True)
listBox1.SetSelected(5, True)
For reference, this is the MSDN article.
Because my code had the following loops:
For i As Integer = 0 To Me.lstItemSizes.Items.Count - 1
For x As Integer = 0 To itemSizes.Count - 1
If (CType(Me.lstItemSizes.Items(i), PosSize).SizeID = itemSizes(x).SizeID) Then
Me.lstItemSizes.SetSelected(i, True)
Else
Me.lstItemSizes.SetSelected(i, False)
End If
Next
Next
The first loop loops through the available sizes and the second loop is used to compare the item sizes.
Having the following code:
Else
Me.lstItemSizes.SetSelected(i, False)
End If
Meant that even if item i became selected, it could also be deselected.
SOLUTION:
Remove Me.lstItemSizes.SetSelected(i, False) OR Include Exit For