I've 100 buttons created dynamically in a form. How can I an add event handler to them?
Simply add the eventhandler to the button when creating it. button. Click += new EventHandler(this. button_Click); void button_Click(object sender, System.
How can I call SubGraphButton_Click(object sender, RoutedEventArgs args) from another method? private void SubGraphButton_Click(object sender, RoutedEventArgs args) { } private void ChildNode_Click(object sender, RoutedEventArgs args) { // call SubGraphButton-Click(). }
To simulate the button click in code, you simply call the event handler: Button1_Click(object sender, EventArgs e). protected void Page_Load(object sender, EventArgs e) { //This simulates the button click from within your code. Button1_Click(Button1, EventArgs.
You can use AddHandler to add a handler for any event.
For example, this might be:
AddHandler theButton.Click, AddressOf Me.theButton_Click
Just to round out Reed's answer, you can either get the Button
objects from the Form
or other container and add the handler, or you could create the Button
objects programmatically.
If you get the Button
objects from the Form
or other container, then you can iterate over the Controls
collection of the Form
or other container control, such as Panel
or FlowLayoutPanel
and so on. You can then just add the click handler withAddHandler ctrl.Click, AddressOf Me.Button_Click
(variables as in the code below),
but I prefer to check the type of the Control
and cast to a Button
so as I'm not adding click handlers for any other controls in the container (such as Labels). Remember that you can add handlers for any event of the Button
at this point using AddHandler
.
Alternatively, you can create the Button
objects programmatically, as in the second block of code below.
Then, of course, you have to write the handler method, as in the third code block below.
Here is an example using Form
as the container, but you're probably better off using a Panel
or some other container control.
Dim btn as Button = Nothing
For Each ctrl As Control in myForm.Controls
If TypeOf ctrl Is Button Then
btn = DirectCast(ctrl, Button)
AddHandler btn.Click, AddressOf Me.Button_Click ' From answer by Reed.
End If
Next
Alternatively creating the Button
s programmatically, this time adding to a Panel
container.
Dim Panel1 As new Panel()
For i As Integer = 1 to 100
btn = New Button()
' Set Button properties or call a method to do so.
Panel1.Controls.Add(btn) ' Add Button to the container.
AddHandler btn.Click, AddressOf Me.Button_Click ' Again from the answer by Reed.
Next
Then your handler will look something like this
Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
' Handle your Button clicks here
End Sub
@Debasish Sahu, your answer is an answer to another question, namely: how to know which button (or any other control) was clicked when there is a common handler for a couple of controls? So I'm giving an answer to this question how I usually do it, almost the same as yours, but note that also works without type conversion when it handles the same type of Controls:
Private Sub btn_done_clicked(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim selectedBtn As Button = sender
MsgBox("you have clicked button " & selectedBtn.Name)
End Sub
I needed a common event handler in which I can show from which button it is called without using switch case... and done like this..
Private Sub btn_done_clicked(ByVal sender As System.Object, ByVal e As System.EventArgs)
MsgBox.Show("you have clicked button " & CType(CType(sender, _
System.Windows.Forms.Button).Tag, String))
End Sub
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