Why did they do this ? - Xtreme Visual Basic Talk

06-10-2012, 01:16 AM

philman

Freshman

Join Date: Mar 2011

Posts: 32

Why did they do this ?

I have been going through a tutorial and came across this code:

Code:

Private Delegate Sub DisplayTextCallback(ByVal Text As String)
Private Sub CallDisplayTextCallback(ByVal Text As String)
        Dim cb As New DisplayTextCallback(AddressOf DisplayText)
        Dim args() As Object = {Text}  
        Me.Invoke(cb, args)
End Sub

I replaced the last 2 lines of the sub with:

Code:

Me.Invoke(cb, Text)

and it works perfectly.

Why did they create an object array?
Is it okay to use the "Text" keyword as a variable?

I would greatly appreciate any explanations.

06-10-2012, 06:36 AM

snarfblam

Senior Contributor

Forum Leader
* Expert *

Join Date: Apr 2005

Location: USA

Posts: 866

Just look at the documentation:

Code:

'Declaration
Public Function Invoke ( _
	method As Delegate, _
	ParamArray args As Object() _
) As Object

That "ParamArray" means that you can pass as many arguments as you wish, and they will automatically be placed in an array. That's what you did in your second code listing. Alternatively, you can explicitly create the array and pass it. That's what you did in your first code listing.

Quote:

Is it okay to use the "Text" keyword as a variable?

If you are asking if it's okay to use the Text variable as an argument, then yes, absolutely.

__________________
C# _VB.NET _

06-10-2012, 07:05 AM

philman

Freshman

Join Date: Mar 2011

Posts: 32

Thanks Snarfblam