How to programmatically add controls to a form in VB.NET - vb.net

Question

I am working on an inventory in Visual Basic 2010 Express Edition. I don't know the number of fields that will be necessary for the inventory. My hope was that I could add textboxes/checkboxes/buttons using for loops in the program. Is there a way to add controls to a form without using the toolbox?
Can I add controls by instantiating them in the program?

Answer 1

Yes.
Private Sub MyForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim MyTextbox as New Textbox
With MyTextbox
.Size = New Size(100,20)
.Location = New Point(20,20)
End With
AddHandler MyTextbox.TextChanged, AddressOf MyTextbox_Changed
Me.Controls.Add(MyTextbox)
'Without a help environment for an intelli sense substitution
'the address name and the methods name
'cannot be wrote in exchange for each other.
'Until an equality operation is prior for an exchange i have to work
'on an as is base substituted.
End Sub
Friend Sub MyTextbox_Changed(sender as Object, e as EventArgs)
'Write code here.
End Sub

Answer 2

Dim numberOfButtons As Integer
Dim buttons() as Button
Private Sub MyForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Redim buttons(numberOfbuttons)
for counter as integer = 0 to numberOfbuttons
With buttons(counter)
.Size = (10, 10)
.Visible = False
.Location = (55, 33 + counter*13)
.Text = "Button "+(counter+1).ToString ' or some name from an array you pass from main
'any other property
End With
'
next
End Sub
If you want to check which of the textboxes have information, or which radio button was clicked, you can iterate through a loop in an OK button.
If you want to be able to click individual array items and have them respond to events, add in the Form_load loop the following:
AddHandler buttons(counter).Clicked AddressOf All_Buttons_Clicked
then create
Private Sub All_Buttons_Clicked(ByVal sender As System.Object, ByVal e As System.EventArgs)
'some code here, can check to see which checkbox was changed, which button was clicked, by number or text
End Sub
when you call: objectYouCall.numberOfButtons = initial_value_from_main_program
response_yes_or_no_or_other = objectYouCall.ShowDialog()
For radio buttons, textboxes, same story, different ending.

Answer 3

Public Class Form1
Private boxes(5) As TextBox
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim newbox As TextBox
For i As Integer = 1 To 5 'Create a new textbox and set its properties26.27.
newbox = New TextBox
newbox.Size = New Drawing.Size(100, 20)
newbox.Location = New Point(10, 10 + 25 * (i - 1))
newbox.Name = "TextBox" & i
newbox.Text = newbox.Name 'Connect it to a handler, save a reference to the array & add it to the form control.
AddHandler newbox.TextChanged, AddressOf TextBox_TextChanged
boxes(i) = newbox
Me.Controls.Add(newbox)
Next
End Sub
Private Sub TextBox_TextChanged(sender As System.Object, e As System.EventArgs)
'When you modify the contents of any textbox, the name of that textbox
'and its current contents will be displayed in the title bar
Dim box As TextBox = DirectCast(sender, TextBox)
Me.Text = box.Name & ": " & box.Text
End Sub
End Class

Answer 4

To add controls dynamically to the form, do the following code. Here we are creating textbox controls to add dynamically.
Public Class Form1
Private m_TextBoxes() As TextBox = {}
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles Button1.Click
' Get the index for the new control.
Dim i As Integer = m_TextBoxes.Length
' Make room.
ReDim Preserve m_TextBoxes(i)
' Create and initialize the control.
m_TextBoxes(i) = New TextBox
With m_TextBoxes(i)
.Name = "TextBox" & i.ToString()
If m_TextBoxes.Length < 2 Then
' Position the first one.
.SetBounds(8, 8, 100, 20)
Else
' Position subsequent controls.
.Left = m_TextBoxes(i - 1).Left
.Top = m_TextBoxes(i - 1).Top + m_TextBoxes(i - _
1).Height + 4
.Size = m_TextBoxes(i - 1).Size
End If
' Save the control's index in the Tag property.
' (Or you can get this from the Name.)
.Tag = i
End With
' Give the control an event handler.
AddHandler m_TextBoxes(i).TextChanged, AddressOf TextBox_TextChanged
' Add the control to the form.
Me.Controls.Add(m_TextBoxes(i))
End Sub
'When you enter text in one of the TextBoxes, the TextBox_TextChanged event
'handler displays the control's name and its current text.
Private Sub TextBox_TextChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs)
' Display the current text.
Dim txt As TextBox = DirectCast(sender, TextBox)
Debug.WriteLine(txt.Name & ": [" & txt.Text & "]")
End Sub
End Class

Answer 5

You can get your Button1 location and than increase the Y value every time you click on it.
Public Class Form1
Dim BtnCoordinate As Point
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim btn As Button = New Button
BtnCoordinate.Y += Button1.Location.Y + 4
With btn
.Location = New Point(BtnCoordinate)
.Text = TextBox1.Text
.ForeColor = Color.Black
End With
Me.Controls.Add(btn)
Me.StartPosition = FormStartPosition.CenterScreen
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Button1Coordinate = Button1.Location
End Sub
End Class