passing class level variable byref

  • Thread starter Thread starter Cc
  • Start date Start date
C

Cc

hi,
how do I pass byref a variable at class level? , something like how dataset
work,event if declare at class level but it always pass as ref.
 
Hi Cc,

I'm afraid that I don't understand your query. Could you give a few more
details, please?

Regards,
Fergus
 
for example
I have form call form1.vb and class call class1.vb . on class1.vb you have
function A and B . if for example u need to pass a variable byref from
form1 to class1 what we usually do is declare function with parameter
passing byref. this is allright if for 1 or 2 function, but if all function
in class1 required the variable tobe pass as ref this could be tedious when
everytime calling the function in class1. that why i ask is there better
solution in this.
 
Cc said:
for example
I have form call form1.vb and class call class1.vb . on class1.vb
you have function A and B . if for example u need to pass a
variable byref from form1 to class1 what we usually do is declare
function with parameter passing byref. this is allright if for 1 or 2
function, but if all function in class1 required the variable tobe
pass as ref this could be tedious when everytime calling the function
in class1. that why i ask is there better solution in this.
Click to expand...

I hope I understood you right. First, you only need to pass the Form "ByRef"
if you want to create a *new* Form in class1. If you don't create a new Form
in Class1, pass the Form ByVal. Second, why don't you write the code in
Form1?
 
Cc said:
I have form call form1.vb and class call class1.vb .
on class1.vb you have function A and B . if for example
u need to pass a variable byref from form1 to class1 what
we usually do is declare function with parameter
passing byref.
Click to expand...

Make sure you understand the difference between 'ByVal' and 'ByRef' for
reference types:

\\\
Public Sub Main()
Dim sb As New StringBuilder("BBB")
changeit1(sb)
MsgBox(sb.ToString())
sb = New StringBuilder("BBB")
changeit2(sb)
MsgBox(sb.ToString())
System.Console.ReadLine()
End Sub

Private Sub changeit1(ByVal s As StringBuilder)
s = New StringBuilder()
s.Append("Bla")
End Sub

Private Sub changeit2(ByRef s As StringBuilder)
s = New StringBuilder()
s.Append("Bla")
End Sub
///
 
Hi Cc,

|| but if all function in class1 required the variable
|| to be pass as ref this could be tedious when
|| everytime calling the function in class1.

I'm not sure what's tedious about it? Is it too much to type ByRef in your
parameter list ?

However, if the variable that you are passing is an object of any sort, it
is <already> a reference variable and wouldn't need ByRef.

Have I understood your query ?

Regards,
Fergus
 
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