B4J Question How to invoke the event for Sender ?

peacemaker · Mar 27, 2026

Buttons are created dynamically, the single shared event. And key pressing are caught.

B4X:

Private Sub butVar_Click
    Dim b As B4XView = Sender
...

Private Sub KeyPressed_Event(e As Event)
    Dim KE As Reflector
    KE.Target = e 'e is a KeyEvent instance
    Dim KeyCode As String = KE.RunMethod("getCode")
    'Log(KeyCode)
    Dim EventType As String = KE.RunMethod("getEventType")
 
    Select EventType
    
        Case "KEY_PRESSED"
            For i = 0 To 9
                If KeyCode = $"DIGIT${i}"$ Or KeyCode = $"NUMPAD${i}"$ Then
                    ClickButton(i)
                    Exit
                End If

            Next
 
        Case "KEY_RELEASED"     
    End Select
    e.Consume
End Sub
...

But how to invoke butVar_Click for each button according to the keycode via ClickButton(i)?

teddybear · Mar 27, 2026

I don't know how you dynamically create buttons, but you can add a keypressed handler event when creating them.

B4X:

    For i=0 To n
        Dim btn As Button
        btn.Initialize("")
        btn.Tag=i
        ...'Create btn views
        Dim r As Reflector
        r.Target = btn
        r.AddEventHandler("btn_KeyPressed", "javafx.scene.input.KeyEvent.KEY_PRESSED")
    Next
    ...
    Private Sub btn_KeyPressed_Event(e As Event)
    Dim b As Button=Sender
    Log(b.Tag)
    Dim KE As Reflector
    KE.Target = e 'e is a KeyEvent instance
    Dim KeyCode As String = KE.RunMethod("getCode")
    'Log(KeyCode)
    Dim EventType As String = KE.RunMethod("getEventType")
 
    Select EventType
   
        Case "KEY_PRESSED"
            For i = 0 To 9
                If KeyCode = $"DIGIT${i}"$ Or KeyCode = $"NUMPAD${i}"$ Then
                    ClickButton(i)
                    Exit
                End If

            Next
 
        Case "KEY_RELEASED"    
    End Select
    e.Consume
End Sub
...

peacemaker · Mar 27, 2026

teddybear said:
Private Sub btn_KeyPressed_Event(e As Event) Dim b As Button=Sender Log(b.Tag)

No, here the Sender is some panel. I guess, the form itself, it's 600x600 px

peacemaker · Mar 27, 2026

DonManfred said:
[B4X] I need 100 <custom view here>s. How to add programmatically?

Custom views are designed to be added with the designer. It is however very simple to create a layout file with the custom view and load it multiple times. Tip: remove the call to AutoScaleAll from the designer script. Complete example: Sub Globals Private B4XSwitch1 As B4XSwitch End...

www.b4x.com

Yes, buttons created by this way. Question is how to run buttons actions if the one single event without a parameter.

teddybear · Mar 27, 2026

peacemaker said:
Yes, buttons created by this way. Question is how to run buttons actions if the one single event without a parameter.

It can also capture the keypress event of a specific button. could you upload a small project for that?

peacemaker · Mar 27, 2026

teddybear said:
could you upload a small project for that?

teddybear · Mar 27, 2026

I got you. it should work for you.

B4X:

Sub ClickButton(i As Int)
    For Each b As Button In created_buttons
        If i-1 = b.Tag Then
            b.As(JavaObject).RunMethod("fire", Null)
            Exit
        End If
    Next
End Sub

peacemaker · Mar 27, 2026

teddybear said:
b.As(JavaObject).RunMethod("fire", Null)

Wow! Indeed, "fire" is the root.
Thanks for help !

B4J Question How to invoke the event for Sender ?

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[B4X] I need 100 <custom view here>s. How to add programmatically?

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