Adding Controls/Event Handlers Programmatically...

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VagabondSW

Regular
Joined
Feb 19, 2005
Messages
66
I need a bit of a kick-in-the-rear to get me on the right track. I have programmatically added buttons to a Panel, but I now need to handle the click event of each of those buttons.

I have a sub-routine that creates an instance of a Button and adds it to the Panel.Controls collection. Once the end of that sub-routine is reached, the instance of those buttons are out of scope.

Is there a way to programmatically create the event handlers for the buttons in the Panel.Controls collection or do I need to Declare a Button Array and add them to that in order to support event handling? Does that make sense?

Visual Basic: 
Private Sub MakePanelControlTop()

   Dim buttonAdd As New Button
   With buttonAdd
      .FlatStyle = FlatStyle.Flat
      .Name = Me.BUTTON_NAME_ADD
      .Text = Me.BUTTON_TEXT_ADD
   End With
   PanelControlTop.Controls.Add(buttonAdd)
   Me.MakeToolTip(buttonAdd, Me.TOOLTIP_TEXT_BTNADD)

   Dim buttonRemove As New Button
   With buttonRemove
      .FlatStyle = FlatStyle.Flat
      .Name = Me.BUTTON_NAME_REMOVE
      .Text = Me.BUTTON_TEXT_REMOVE
   End With
   PanelControlTop.Controls.Add(buttonRemove)
   Me.MakeToolTip(buttonRemove, Me.TOOPTIP_TEXT_BTNREMOVE)

   Dim buttonClear As New Button
   With buttonClear
      .FlatStyle = FlatStyle.Flat
      .Name = Me.BUTTON_NAME_CLEAR
      .Text = Me.BUTTON_TEXT_CLEAR
   End With
   PanelControlTop.Controls.Add(buttonClear)
   Me.MakeToolTip(buttonClear, Me.TOOLTIP_TEXT_BTNCLEAR)

   Dim buttonApply As New Button
   With buttonApply
      .FlatStyle = FlatStyle.Flat
      .Name = Me.BUTTON_NAME_APPLY
      .Text = Me.BUTTON_TEXT_APPLY
   End With
   PanelControlTop.Controls.Add(buttonApply)
   Me.MakeToolTip(buttonApply, Me.TOOLTIP_TEXT_BTNAPPLY)

End Sub
 
Why are you doing this anyway? Where are the BUTTON_NAME_ADD, BUTTON_NAME_REMOVE being kept? A resource file?

You should set the location and visibility of each button, otherwise they may not show up and if they do they will all be in location 0, 0.

Since you are creating each button seperately, you can handle each event in it's own function

eg.

Visual Basic: 
Dim buttonAdd As New Button
   With buttonAdd
      .FlatStyle = FlatStyle.Flat
      .Name = Me.BUTTON_NAME_ADD
      .Text = Me.BUTTON_TEXT_ADD
      .Visible = True
      .Location = new Point(10, 10)
     End With
   AddHandler buttonAdd.Click, AddressOf Crap

   PanelControlTop.Controls.Add(buttonAdd)
   Me.MakeToolTip(buttonAdd, Me.TOOLTIP_TEXT_BTNADD)

Public Sub Crap(sender as object, e as EventArgs)
   'handle click event
End Sub

  Dim buttonRemove As New Button
   With buttonRemove
      .FlatStyle = FlatStyle.Flat
      .Name = Me.BUTTON_NAME_REMOVE
      .Text = Me.BUTTON_TEXT_REMOVE
      .Visible = True
      .Location = new Point(80, 10)
   End With

   AddHandler buttonRemove.Click, AddressOf Crap2
   PanelControlTop.Controls.Add(buttonRemove)
   Me.MakeToolTip(buttonRemove, Me.TOOPTIP_TEXT_BTNREMOVE)

Public Sub Crap2(sender as object, e as EventArgs)
'handle remove button click
End Sub
 
Diesel said:
Why are you doing this anyway? Where are the BUTTON_NAME_ADD, BUTTON_NAME_REMOVE being kept? A resource file?

You should set the location and visibility of each button, otherwise they may not show up and if they do they will all be in location 0, 0.

Since you are creating each button seperately, you can handle each event in it's own function
Click to expand...

The BUTTON_NAME_ADD and BUTTON_NAME_REMOVE are constants, currently declared in the same class (custom control). The location of each is set in another method based the locations of other controls (on this custom control) and the size of this custom control's Parent, etc.

I don't think the Crap event handler would work because buttonAdd no longer exists outside of the method that created it. When I use the AddHandler/AddressOf line as you have suggested, my Crap event handler produces an error message:

FilterBuilder.vb(659): 'buttonAdd' is not an event of FilterBuilder'.​

I think these buttons are improperly scoped. I will probably need class-level availability rather than simply method level availability for these buttons specifically.
 
Nevermind. I am slowly kicking my own rear into gear on this subject. I was improperly declaring the Event Handler. I'll follow-up with my code when I have it all working.
 
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