reusing sub routines

  • Thread starter Thread starter sevenfoot
  • Start date Start date
S

sevenfoot

how can I make one subroutine to handle events from different objects?
For instance I have six panels that do the same thing when something
is dragged into them, I'd like to have one subroutine to do this
rather than have six.

Private Sub Panel0_DragEnter(ByVal sender
As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles
Panel0.DragEnter
If (e.Data.GetDataPresent(DataFormats.Text))
Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.None
End If
End Sub

Private Sub Panel1_DragEnter(ByVal sender As Object, ByVal e
As System.Windows.Forms.DragEventArgs) Handles Panel1.DragEnter
If (e.Data.GetDataPresent(DataFormats.Text))
Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.None
End If
End Sub

here's two of the subroutines, the only thing that changes is the name
of the panel.


thanks,
Jason
 
.... Handles Panel0.DragEnter, Panel1.DragEnter, Panel2.DragEnter, ...

or use AddHandler ...

how can I make one subroutine to handle events from different objects?
For instance I have six panels that do the same thing when something
is dragged into them, I'd like to have one subroutine to do this
rather than have six.

Private Sub Panel0_DragEnter(ByVal sender
As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles
Panel0.DragEnter
If (e.Data.GetDataPresent(DataFormats.Text))
Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.None
End If
End Sub

Private Sub Panel1_DragEnter(ByVal sender As Object, ByVal e
As System.Windows.Forms.DragEventArgs) Handles Panel1.DragEnter
If (e.Data.GetDataPresent(DataFormats.Text))
Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.None
End If
End Sub

here's two of the subroutines, the only thing that changes is the name
of the panel.


thanks,
Jason
Click to expand...
 
Jason,
As John stated, you can list multiple objects in the Handles clause or use
AddHandler.

The other thing that is useful to know is the "sender" parameter to the
event handler is the object raising the event.

For example you can use the sender to change the background color of the
panel when you are dragging over that panel, with something like:
Private Sub Panel0_DragEnter(ByVal sender
As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles
Panel0.DragEnter, Panel1.DragEnter
Click to expand...
If TypeOf sender Is Panel Then
Dim thePanel As Panel = DirectCast(sender, Panel)
thePanel.BackGround = Color.Red
End If

...
End Sub
Click to expand...
Private Sub Panel0_DragLeave(ByVal sender
As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles
Panel0.DragLeave, Panel1.DragLeave
Click to expand...
If TypeOf sender Is Panel Then
Dim thePanel As Panel = DirectCast(sender, Panel)
thePanel.BackGround = System.Colors.Control
End If

...
End Sub
Click to expand...

Hope this helps
Jay

sevenfoot said:
how can I make one subroutine to handle events from different objects?
For instance I have six panels that do the same thing when something
is dragged into them, I'd like to have one subroutine to do this
rather than have six.

Private Sub Panel0_DragEnter(ByVal sender
As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles
Panel0.DragEnter
If (e.Data.GetDataPresent(DataFormats.Text))
Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.None
End If
End Sub

Private Sub Panel1_DragEnter(ByVal sender As Object, ByVal e
As System.Windows.Forms.DragEventArgs) Handles Panel1.DragEnter
If (e.Data.GetDataPresent(DataFormats.Text))
Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.None
End If
End Sub

here's two of the subroutines, the only thing that changes is the name
of the panel.


thanks,
Jason
Click to expand...
 
Back
Top