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Adding controls withevents at runtime in VB .NET

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Submitted on: 1/1/2015 2:34:00 AM
By: Sahand (from psc cd)  
Level: Beginner
User Rating: By 13 Users
Compatibility: VB.NET
Views: 6254
 
     Sometimes it is necessary to add controls at runtime or use a dynamic array of controls and you want to have events too , this tutorial will show you how to do this.

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Adding controls at runtime

First of all you need to declare an array of that control but you can't do that by the withevents statement so you first need to create a class that has the events in itself then you delare an array of that class. in the examples below i will make a program with a button that when it is pressed it will add a textbox to the form in a random location. here's the definition of the class:
(in this example only the TextChanged event is rewritten but you can do it with all the events)

Public Class MyTextBox 
Inherits System.Windows.Forms.TextBox 
Private Sub MyTextBox_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.TextChanged 
MsgBox(Me.Name & "'s text changed!") 
End Sub
End Class

Then you declare an array of this class in the Form class like this:

Private TextBoxes() as MyTextBox



then assuming that you have a Button with the name of 'Button1' you write the following code in the Clicked event:

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Static num As Integer
num += 1
ReDim TextBoxes(num)
TextBoxes(num - 1) = New MyTextBox()
With TextBoxes(num - 1)
 .Name = "Textbox" & num
 .Text = "Textbox" & num
 .Location = New System.Drawing.Point(10, num * (.Height + 10))
End With
Me.Controls.AddRange(New System.Windows.Forms.Control() {TextBoxes(num - 1)}) End Sub End Class

then TextBox appears on the form , so that's it.

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