How to access several dymanically created Combobox at form load? - arrays

I'm creating comboboxes on form load, but the thing is once I have added a new cb I can't access (set value, edit properties, etc) of the prior ones.
See Below Example:
Sub Start_stackoverflow()
Dim strings() As String = {"Green", "Purple", "Red"}
Dim x as integer
For x = LBound(strings) To UBound(strings)
NewDropDown(x,50,100,strings(x),strings(x))
Next x
End Sub
Private Sub NewDropDown(ByVal Number As Integer, ByVal PosX As Integer, ByVal PosY As Integer, ByVal Name As String, ByVal Text As String)
cbComboBox = New ComboBox
cbComboBox.Location = New Point(150, PosY - 4%)
cbComboBox.Name = Number
cbComboBox.ForeColor = Color.White
cbComboBox.BackColor = Color.DarkBlue
cbComboBox.Text = Name
cbComboBox.AutoSize = True
Me.Controls.Add(cbComboBox)
End Sub
So this is what happens, I can create the comboboxes just fine, add the values but if I wanted to edit the combobox Green for example (since it was first) I cant.
Even If I try this:
Sub Test()
UpdateComboBoxCurrentlySelected(Green, MyValueIwantSelected)
End Sub
Sub UpdateComboBoxCurrentlySelected(ByVal SetGrpName As ComboBox, ByVal CurrentItem As String)
SetGrpName.Text = (CurrentItem)
SetGrpName.SelectedText = (CurrentItem)
SetGrpName.SelectedItem = (CurrentItem)
SetGrpName.SelectedIndex = (CurrentItem)
SetGrpName.SelectedValue = (CurrentItem)
End Sub
Can anyone shed some light on this, that way I will know how to do it properly.
Thanks

You either need to hold a reference to the object you want to edit:
' At form level
Private dropdowns As Dictionary(Of String, Combobox) = New Dictionary(Of String, ComboBox)
' Populate from Sub Start_stackoverflow()
Dim dropdown As ComboBox = Nothing
' ...
dropdown = NewDropDown(x,50,100,strings(x),strings(x))
dropdowns.Add(dropdown.Name, dropdown)
' change UpdateComboBoxCurrentlySelected signature to
Sub UpdateComboBoxCurrentlySelected(ByVal SetGrpName As String, ByVal CurrentItem As String)
' get the dropdown by name
Dim dropdown as ComboBox = dropdowns(SetGrpName)
' ...
Or you can iterate over all the controls in the form looking for the one with the name you asked for.
Dim foundControl As ComboBox = Nothing
For Each control As Control In Me.Controls
If control.GetType Is GetType(ComboBox) AndAlso (control.Name = SetGrpName) Then
foundControl = control
End If
Next
If Not Nothing Is foundControl Then
' Do something with your control.
End If

Related

VB.NET add or subtract an integer value to a SQL Server value into a label when selecting a combobox item

Following my previous question answered by #Andrew Morton, I have one more :)
Here is my whole code (not very long for now) :
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.Sql
Public Class Form1
Sub PopulateCB()
Dim connection As String = "Data Source=.\SQLEXPRESS;Initial Catalog=OST;Integrated Security=True"
Dim sql = "SELECT * FROM liste_unités"
Dim dt As New DataTable
Using conn As New SqlConnection(connection),
da As New SqlDataAdapter(sql, conn)
da.Fill(dt)
End Using
ComboBoxC1L1.DataSource = dt
ComboBoxC1L1.DisplayMember = "nom_unité"
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
PopulateCB()
End Sub
Private Sub ComboBoxC1L1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBoxC1L1.SelectedIndexChanged
Dim cb = DirectCast(sender, ComboBox)
If cb.SelectedIndex >= 0 Then
Dim val = DirectCast(cb.SelectedItem, DataRowView).Row.Field(Of Integer)("cout_unité")
If ComboBoxQC1L1.Text = "ordinaire" Then
LabelPointsC1L1.Text = val
ElseIf ComboBoxQC1L1.Text = "médiocre" Then
LabelPointsC1L1.Text = val - 2
ElseIf ComboBoxQC1L1.Text = "élite" Then
LabelPointsC1L1.Text = val + 2
End If
If cb.SelectedIndex >= 0 Then
Dim val2 = DirectCast(cb.SelectedItem, DataRowView).Row.Field(Of String)("type_unité")
LabelUnitType.Text = val2
End If
End If
Try
Dim totalC1L1 As Integer
totalC1L1 = CInt(TextBoxC1L1.Text) * CInt(LabelPointsC1L1.Text)
LabelTotalC1L1.Text = totalC1L1
Catch ex As Exception
End Try
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
ComboBoxQC1L1.Text = "ordinaire"
End Sub
Private Sub TextBoxC1L1_TextChanged(sender As Object, e As EventArgs) Handles TextBoxC1L1.TextChanged
Try
Dim totalC1L1 As Integer
totalC1L1 = CInt(TextBoxC1L1.Text) * CInt(LabelPointsC1L1.Text)
LabelTotalC1L1.Text = totalC1L1
Catch ex As exception
End Try
End Sub
End Class
Here is the program interface
Here is the SQL table look
Here is the program interface when the Button has been clicked
Red Arrow ComboBox text is a DropDownStyle box with 3 possible text choices:
ordinaire,
élite,
médiocre
What I want to do: when changing the red arrow combobox text, the cout_unité label should change too with a "cout_unité -2" in case of "médiocre" ComboBox text, or "cout_unité +2" in case of "élite" ComboBox text or remain = to "cout_unité" if the selected text is "ordinaire".
And it should calculate this only once from the original "cout_unité" value in the table (in case of clicking 10 times on "ordinaire", it shouldn't subtract 10 * 2 to the "cout_unité" value, only 1 * 2)
I can do it in the ComboBoxC1L1 (see code) but I can't reproduce it with this red arrow combobox (probably because of the type of data into this combobox which are "strings", I don't know).
Many thanks :)
Since there is only a single Handles clause, the following line is unnecessary. The sender can only be the ComboBox in the Handles.
Dim cb = DirectCast(sender, ComboBox)
If you set the ValueMember of the combo in the PopulateCB method, you can save a long line of code making the code more readable.
Dim val = DirectCast(cb.SelectedItem, DataRowView).Row.Field(Of Integer)("cout_unité")
To:
Dim val = CInt(ComboBoxC1L1.SelectedValue)
We need the CInt since SelectedValue is an Object.
Don't assign the DataSource until after the DisplayMember and ValueMember are set.
You are checking twice for ComboBoxC1L1.SelectedIndex >= 0.
Just include the unit type in the first If.
The user may not have to trigger the SelectedIndexChanged event if the correct value is already selected. Maybe a button click would be better.
Sub PopulateCB()
Dim connection As String = "Data Source=.\SQLEXPRESS;Initial Catalog=OST;Integrated Security=True"
Dim sql = "SELECT * FROM liste_unités"
Dim dt As New DataTable
Using conn As New SqlConnection(connection),
da As New SqlDataAdapter(sql, conn)
da.Fill(dt)
End Using
ComboBoxC1L1.DisplayMember = "nom_unité"
ComboBoxC1L1.ValueMember = "cout_unité"
ComboBoxC1L1.DataSource = dt
End Sub
Private Sub btnCalculateValue_Click(sender As Object, e As EventArgs) Handles btnCalculateValue.Click
If ComboBoxC1L1.SelectedIndex >= 0 Then
Dim val = CInt(ComboBoxC1L1.SelectedValue)
If ComboBoxQC1L1.Text = "ordinaire" Then
LabelPointsC1L1.Text = val.ToString
ElseIf ComboBoxQC1L1.Text = "médiocre" Then
LabelPointsC1L1.Text = (val - 2).ToString
ElseIf ComboBoxQC1L1.Text = "élite" Then
LabelPointsC1L1.Text = (val + 2).ToString
End If
Dim val2 = DirectCast(ComboBoxC1L1.SelectedItem, DataRowView).Row.Field(Of String)("type_unité")
LabelUnitType.Text = val2
End If
Dim totalC1L1 As Integer
totalC1L1 = CInt(TextBoxC1L1.Text) * CInt(LabelPointsC1L1.Text)
LabelTotalC1L1.Text = totalC1L1.ToString
End Sub

Unable to WRAP text in an Autocomplete Textbox column of DataGridView

I created an Autocomplete Textbox column in DataGridView (Works Fine).
See this image. This is what I have
Now there is no problem until the text size is small but when the text gets longer it doesn't get wrapped in the column, the text gets trimmed.
This is the Problem
If I set the WRAP property of the column to TRUE then the textbox stops Autocompleting.
SO, its like either auto-completing or WRAPPING, but I need both...
I am putting my code below if anything can be done within it, have a look -
Private Sub DataGridView2_EditingControlShowing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridView2.EditingControlShowing
DataGridView2.BeginEdit(True)
Dim autoText As TextBox = TryCast(e.Control, TextBox)
If autoText IsNot Nothing Then
autoText.AutoCompleteMode = AutoCompleteMode.SuggestAppend
autoText.AutoCompleteCustomSource = AutoCompleteLoad()
autoText.AutoCompleteSource = AutoCompleteSource.CustomSource
End If
End Sub
Public Function AutoCompleteLoad() As AutoCompleteStringCollection
Dim str As AutoCompleteStringCollection = New AutoCompleteStringCollection()
Dim ConnectionString As SqlConnection = New SqlConnection("data source=ADMIN-PC\SQLEXPRESS; database=billdev;Trusted_Connection=yes;")
Dim strSQL As String = "SELECT particulars from bill;"
Dim SQLcommand As New SqlCommand(strSQL, ConnectionString)
ConnectionString.Open()
Dim reader As SqlDataReader
reader = SQLcommand.ExecuteReader()
While reader.Read()
str.Add(reader.Item(0))
End While
Return str
End Function
[SOLVED]
Maybe it has a bug in datagridview control.
we can do one cheat method to solve this issue.
in Datagridview_CellBegainEdit, set rowsDefaultcellstyle wrapmode = false
in DatagridView_CellEndEdit, set rowsDefaultcellstyle wrapmode = true
Example:
DGV.RowsDefaultCellStyle.WrapMode = DataGridViewTriState.False (CellBegainEdit)
DGV.RowsDefaultCellStyle.WrapMode = DataGridViewTriState.True (CellEndEdit)
Its working for me.

create array of existing buttons vb 2013

I used to program in VB6 and am trying to write the same program in VB 2013. In this program I use an array of 49 buttons that all do the same thing when you click on them. I have figured out have to do the click function to a point:
Private Sub Button_Click(sender As Object, e As EventArgs) Handles Button9.Click, Button10.Click, Button11.Click, Button12.Click, Button13.Click, Button16.Click, Button17.Click, Button18.Click, Button19.Click, Button20.Click
...
End Sub
What I am trying to do is simplify the code down to using an array so I can just pass on the index. One other person asked the same question in 2010 and the best answer was:
Button[] array = { firstButton, secondButton };
That would work but I want something with less typing. I also tried the following with failure:
One
Button[] buttons = this.Controls.OfType<Button>().ToArray();
Two
For i = 1 To 100
Dim btns() As Button = Controls.Find("Button" & i, True)
Dim btn As Button
If btns IsNot Nothing Then
btn = btns(0)
'If buttons Is Nothing Then
' ReDim buttons(0)
'Else
' ReDim Preserve buttons(buttons.Length)
'End If
'buttons(UBound(buttons)) = btn
btn.Text = i - 1 'here you can change whatever you want
End If
Next
Three
Dim buttons() As Button
buttons = Nothing
For Each b As Button In Me.Controls
If buttons Is Nothing Then
ReDim buttons(0)
Else
ReDim Preserve buttons(buttons.Length)
End If
buttons(UBound(buttons)) = b
Next
I just can't get it to accept the existing buttons into an array. I hope someone can help.
If your Buttons are nested inside container controls (e.g. a GroupBox) then you will need to perform a recursive search for all buttons. Maybe something like this (totally unoptimized)...
Private Function FindAllButtons(root As Control) As List(Of Button)
Dim result As List(Of Button) = New List(Of Button)()
For Each c As Control In root.Controls
If TypeOf c Is Button Then
result.Add(DirectCast(c, Button))
ElseIf c.HasChildren Then
result.AddRange(FindAllButtons(c))
End If
Next
Return result
End Function
Then just call that in your Form:
Dim allButtons as List(Of Button) = FindAllButtons(Me)
' Add common Click handler
For Each b As Button In allButtons
AddHandler b.Click, AddressOf Button_Click
Next
Update Just for fun, here's a generic version to find other types of control.
Private Function FindAllControls(Of T As Control)(root As Control) As List(Of T)
Dim result As List(Of T) = New List(Of T)()
For Each c As Control In root.Controls
If TypeOf c Is T Then
result.Add(DirectCast(c, T))
ElseIf c.HasChildren Then
result.AddRange(FindAllControls(Of T)(c))
End If
Next
Return result
End Function
You can use that like:
Dim allButtons As List(Of Button) = FindAllControls(Of Button)(Me)
Dim allTextBoxes As List(Of TextBox) = FindAllControls(Of TextBox)(Me)
Option two will work, you just need to add the button found into a list. I suggest you add your buttons into a List(Of ) instead of an array. You can always convert the list into an array if you really need to.
Dim buttonList As New List(Of Button)
For i As Integer = 1 To 100
Dim btns() As Control = Controls.Find("Button" & i, True)
If btns IsNot Nothing AndAlso btns.Length > 0 Then
buttonList.Add(CType(btns(0), Button))
End If
Next

Saving nameless textboxes into Database in VB.NET

I'm a student currently doing my programming coursework. I have created a piece of code which creates text boxes for the user to input the names of tracks from a vinyl. As you can choose the amount of text boxes you create, these text boxes end up not having a name (e.g. textbox1, textbox2...), this makes me unsure of how to send the values of the textboxes to the database table. The table is currently empty and only has one column. Could someone please let me know how I will send these values to the database and also the code to create a new column for the tracks. Here is my current code below:
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Label11.Show()
GroupBox1.Show()
GroupBox1.AutoSize = True
Dim number As Integer
number = TextBox8.Text
Dim boxes(number) As TextBox
Dim newbox As TextBox
For i As Integer = 1 To number
newbox = New TextBox
newbox.Size = New Drawing.Size(100, 20)
newbox.Location = New Point(10, 10 + 25 * (i - 1))
AddHandler newbox.TextChanged, AddressOf TextBox_TextChanged
boxes(i) = newbox
GroupBox1.Controls.Add(newbox)
newbox.Name = ("Trackbox" & i)
Next
End Sub
Your boxes array needs to be declared at form level.
Private boxes() As TextBox
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Label11.Show()
GroupBox1.Show()
GroupBox1.AutoSize = True
Dim number As Integer
'need to insert validation code here to make sure a number is entered in TextBox8
number = Integer.Parse(TextBox8.Text)
ReDim boxes(number)
Dim newbox As TextBox
For i As Integer = 1 To number
newbox = New TextBox
newbox.Size = New Drawing.Size(100, 20)
newbox.Location = New Point(10, 10 + 25 * (i - 1))
AddHandler newbox.TextChanged, AddressOf TextBox_TextChanged
GroupBox1.Controls.Add(newbox)
newbox.Name = ("Trackbox" & i.ToString)
boxes(i) = newbox
Next
End Sub
Then you can reference your text boxes as follows:
MessageBox.Show(boxes(5).Text)

VB.NET: DYNAMICALLY ADD ARRAY TO COMBOBOX

Does anyone know how to dynamically add an array to a bunch of comboboxes in VB.net? I could really use the help (I've been struggling with this all day). When I try to do it my way I get an error on form load.
My code:
Private Sub Form1_Load(ByVal sender as Object, ByVal e as EventArgs) Handles Me.Load
Dim MyArray() as String = {"a","b","c"}
For each ctl as ComboBox in Me.Controls
if ctl.tag = "yadda" then ctl.Items.AddRange(MyArray)
Next
End Sub
Error: "Unable to cast object of type '...Button' to type '...Combobox'."
I've tried so many variations to this code but I just can't get it to work. I will eventually have nearly a hundred similarly constructed comboboxes in my application, and I'd like to be able to programmatically initialize their items. Could someone please help?
Thanks,
Elias
This is the way to do it :
Public Class Form1
Function getControl(ByVal controlName As String) As Control
Dim numCtrls = Me.Controls.Count()
For I As Integer = 0 To numCtrls - 1
If Me.Controls.Item(I).Name = controlName Then
If TypeOf Me.Controls.Item(I) Is ComboBox Then
Return CType(Me.Controls(controlName), ComboBox)
End If
End If
Next
End Function
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim myArray As Array = {"a", "b", "c"}
Dim myComboBox As ComboBox
For Each ctl As Control In Me.Controls
If TypeOf ctl Is ComboBox Then
If ctl.Tag = "yadda" Then
myComboBox = getControl(ctl.Name)
myComboBox.Items.AddRange(myArray)
End If
End If
Next
End Sub
End Class
You loop through all controls (buttons, combo, etc ...) then you check if it is the type you want (ComboBox) and do whatever you need.
Good luck !

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