I'm new to programming and I need help with something really basic..
I have a form with a datagridview and an "insert" button that opens a popup window (new form). This popup contains labels and textboxes, and 2 buttons (insert & cancel). How do you add event handlers to the buttons inside the popup? For example, if the user clicks "Cancel", the popup should close.
Here's the code I have so far:
Public Sub InsertButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles InsertButton.Click
Dim insertPopup As New Form
insertPopup.Size = New System.Drawing.Size(300, 400)
insertPopup.StartPosition = FormStartPosition.CenterScreen
insertPopup.Show()
Dim acceptButton As New Button
Dim cancelButton As New Button
acceptButton.Location = New System.Drawing.Point(100, 325)
acceptButton.Text = "Insert"
acceptButton.Size = New System.Drawing.Size(85, 24)
acceptButton.TabIndex = 1
cancelButton.Location = New System.Drawing.Point(190, 325)
cancelButton.Text = "Cancel"
cancelButton.Size = New System.Drawing.Size(85, 24)
cancelButton.TabIndex = 2
insertPopup.Controls.Add(acceptButton)
insertPopup.Controls.Add(cancelButton)
End Sub
Thanks for your help.
You use the AddHandler Method to add the proper EventHandler. You will need to be sure to create your handler with the correct signature.
AddHandler acceptButton.Click, AddressOf acceptButton_Click
AddHandler cancelButton.Click, AddressOf cancelButton_Click
Private Sub acceptButton_Click(sender As System.Object, e As System.EventArgs)
End Sub
Private Sub cancelButton_Click(sender As System.Object, e As System.EventArgs)
CType(CType(sender, Button).Parent, Form).Close()
End Sub
Related
how can I control some controls that will be created automatically during the execution of the application?
My add control
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim NewCheckbox As CheckBox
For i As Integer = 2 To 14
NewCheckbox = New CheckBox
NewCheckbox.Size = New Drawing.Size(15, 14)
NewCheckbox.Location = New Point(98, 40)
NewCheckbox.Name = "cbcard" & i
Me.Controls.Add(NewCheckbox)
next
My checkbox control add, I gave an example to create a checkbox control, but it should be valid for any form of control, be it textbox or button.
how can i detect these controls that are not created but will be created during execution?
checkbox name will be cbcard1, cbcard2, cbcard3 up to 14.
but I want this to be in the form of a handler, or it should probably work with a timer.
Private Sub Checkbox_Changed(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Checkbox.Changed
If Checkbox.checked = true
MsgBox("")
End If
End Sub
You can subscribe to the event using the AddHandler syntax.
For i As Integer = 2 To 14
NewCheckbox = New CheckBox
NewCheckbox.Size = New Drawing.Size(15, 14)
NewCheckbox.Location = New Point(98, 40)
NewCheckbox.Name = "cbcard" & i
Me.Controls.Add(NewCheckbox)
'subscribe to the CheckChanged event (as an example)
AddHandler NewCheckbox.CheckChanged, AddressOf Checkbox_Changed
Next
'all dynamically created checkboxes were subscribed to this event
Private Sub Checkbox_Changed(ByVal sender As System.Object, ByVal e As System.EventArgs)
'sender is the specific checkbox that was changed out of all subscribed checkboxes
Dim checkBox = DirectCast(sender, CheckBox)
If checkbox.checked = true Then MsgBox(checkBox.Name)
End Sub
Im currently trying to make dynamically created buttons disappear when clicked.
I have a Private Sub that handles when the button is clicked and increases the players score. However, i do not know how to make the specific object disappear as all the Objects are called the same name as they are created by the same subroutine set on a timer ( a new button made every 2 seconds).
I have tried adding every new button created to an array but am still struggling to make the program figure out which button has been clicked.
Any help would be greatly appreciated.
One of the parameters on your button click event handler should be sender As Object, which is a reference to the button that was clicked. You just need to cast it to a button object, the set the Visible property to false. Here is an example:
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim b As Button = CType(sender, Button)
b.Visible = False
End Sub
Further to #Icemanind's answer, you can actually do it in one line:
CType(sender, Button).Visible = False
This works without validation because you know that sender is of type Button.
If you have multiple buttons to handle, you can also add additional events to the handler so you don't end up with a zillion individual handlers:
Protected Sub Button_Click(s As Object, e As EventArgs) _
Handles _
Button1.Click, Button2.Click, Button3.Click
CType(s, Button).Visible = False
End Sub
Yet another option is to add the same handler to multiple buttons rather than adding buttons to the handler:
In Form instantiation (Sub New()):
AddHandler Button1.Click, AddressOf Button_Click
AddHandler Button2.Click, AddressOf Button_Click
AddHandler Button3.Click, AddressOf Button_Click
In Form class code:
Protected Sub Button_Click(s As Object, e As EventArgs)
CType(s, Button).Visible = False
End Sub
This last method works well with dynamic controls because you can add the handlers on the fly:
Dim button As Button
For i As Integer = 0 To 9
button = New Button With {.Name = $"Button{i}", .Text = $"Button{i}", .Left = 42, .Top = 50 + (i * 30)}
Me.Controls.Add(button)
AddHandler button.Click, AddressOf Button_Click
Next i
I created multiple button dynamically inside a panel based on multiple click on add button. Each button deletes When I click on it.
I want each button to delete when I single click on it, and say hello when I double click. Thank you.
I have tried using this code to delete which works fine, but I cannot figure how to assign seperate code to display hello when I double click or right click on it without affecting delete aspect of it.
Private Sub btnDynamic_Click(ByVal sender As Object, ByVal e As EventArgs)
'Reference the Button which was clicked.
Dim button As Button = CType(sender, Button)
'Determine the Index of the Button.
Dim index As Integer = Integer.Parse(button.Name.Split("_")(1))
'Find the TextBox using Index and remove it.
FlowLayoutPanel1.Controls.Remove(FlowLayoutPanel1.Controls.Find(("btnDynamic_" & index), True)(0))
'Remove the Button.
FlowLayoutPanel1.Controls.Remove(button)
'Rearranging the Location controls.
For Each btn As Button In FlowLayoutPanel1.Controls.OfType(Of Button)()
Dim controlIndex As Integer = Integer.Parse(btn.Name.Split("_")(1))
If (controlIndex > index) Then
Dim btn1 As Button = CType(FlowLayoutPanel1.Controls.Find(("btnDynamic_" & controlIndex), True)(0), Button)
btn1.Top = (btn.Top - 25)
'txt.Top = (txt.Top - 25)
End If
Next
End Sub
Here is the create button code:
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
If TextBox1.Text = "" Then
Exit Sub
End If
Dim count As Integer = Form2.FlowLayoutPanel2.Controls.OfType(Of Button).ToList.Count
Dim button As Button = New Button
button.Size = New System.Drawing.Size(28, 21)
button.Name = "btnDynamic_" & (count + 1)
button.Text = TextBox1.Text
AddHandler button.Click, AddressOf Me.button_click
Form2.FlowLayoutPanel2.Controls.Add(button)
End Sub
You have to enable DoubleClick option first.
You do so with:
Public Class DoubleClickButton
Inherits Button
Public Sub New()
SetStyle(ControlStyles.StandardClick Or ControlStyles.StandardDoubleClick, True)
End Sub
End Class
Then create a "DoubleClick" and "SingleClick" methods and assign them to (new custom) buttons when you are creating them.
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
For x = 0 To 2
Dim ButtonX As New DoubleClickButton
ButtonX.Text = x
AddHandler ButtonX.MouseClick, AddressOf SingleClickE
AddHandler ButtonX.MouseDoubleClick, AddressOf DoubleClickE
FlowLayoutPanel1.Controls.Add(ButtonX)
Next
End Sub
Private Sub SingleClickE(sender As Object, e As MouseEventArgs)
Debug.Print("Hello!")
End Sub
Private Sub DoubleClickE(sender As Object, e As MouseEventArgs)
FlowLayoutPanel1.Controls.Remove(sender)
End Sub
Thank you all for attempting to answer my question. I have been able to figure it out. I intend firing diffrent events with dynamically created buttons using single click, double click or right click. I ended up using single and right click command. Though would have prefered double click, but it is ok. Below is the code.
'Create buttons
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
For i As Integer = 1 To 5
Dim button As New Button
button.Text = i
AddHandler button.Click, AddressOf SingleClickE
AddHandler button.MouseDown, AddressOf RightClickE
FlowLayoutPanel1.Controls.Add(button)
Next
End Sub
'Fire it up with single click
Private Sub SingleClickE(sender As Object, e As MouseEventArgs)
Dim button As Button = CType(sender, Button)
MsgBox("Hello World")
End Sub
'Fire it up with Right Click
Private Sub RightClickE(sender As Object, e As MouseEventArgs)
Dim button As Button = CType(sender, Button)
If e.Button = MouseButtons.Right Then
FlowLayoutPanel1.Controls.Remove(button)
End If
End Sub
My program contains buttons in a FlowLayoutPanel.
I want to disable any button when right click on it and click "Disable" in the ContextMenuStrip.
My code is:
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
For i As Integer = 0 To 30
Dim btn As New Button
btn.Name = i
btn.Text = i
btn.ContextMenuStrip = ContextMenuStrip1
FlowLayoutPanel1.Controls.Add(btn)
Next
End Sub
End Class
declare a public varibale for keeping a control
public ctrl as button = nothing
you can create a right click by putting this code on mouse down...
If e.Button <> Windows.Forms.MouseButtons.Right Then Return
Dim cms = New ContextMenuStrip
ctrl = sender
Dim item1 = cms.Items.Add("Disable")
item1.Tag = 1
AddHandler item1.Click, AddressOf Disable
end if
and in the diable sub you can code like this...
Private Sub Disable()
ctrl.enabled = false
End Sub
I added some controls to my form at runtime and I need them to call a function when clicked. I don't know how many controls will be added but they all need to run the same function. How would I define the event? Can I define events based on all controls of a given class?
A simple example :
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' creating control
Dim btn1 As Button = New Button()
Dim btn2 As Button = New Button()
btn1.Parent = Me
btn1.Name = "btn1"
btn1.Top = 10
btn1.Text = "Btn1"
btn2.Parent = Me
btn2.Name = "btn2"
btn2.Top = 50
btn2.Text = "Btn2"
'adding handler for click event
AddHandler btn1.Click, AddressOf HandleDynamicButtonClick
AddHandler btn2.Click, AddressOf HandleDynamicButtonClick
End Sub
Private Sub HandleDynamicButtonClick(ByVal sender As Object, ByVal e As EventArgs)
Dim btn As Button = DirectCast(sender, Button)
If btn.Name = "btn1" Then
MessageBox.Show("Btn1 clicked")
ElseIf btn.Name = "btn2" Then
MessageBox.Show("Btn2 Clicked")
End If
End Sub
End Class
Simply:
AddHandler Control.Event, AddressOf MethodExecuting
For example:
AddHandler Button1.Click, AddressOf ClickMethod