Classes

[Jay1b]

Hello

 

Could someone pls point me in the right direction with this:

 

If i create a class within one form, how can i use the same instance of that class from within another form?

 

Thanks.

[stustarz]

Firstly ensure the class is a public class, then simply create an object set to the instance of that class:

 

Dim objNewClass As PROJECTNAME.CLASSNAME

 

You can now access the functions etc from the class using the new object

[Jay1b]

Thanks. Call me stupid (i do enough), but here is an example of what i want to do.

 

The Class:

Public Class ClsPrintArgs
   Inherits EventArgs

   Public serial As Integer
   Public printer As String

   Public Sub New(ByVal serial As Integer, ByVal printer As String)
       Me.serial = serial
       Me.printer = printer
   End Sub
End Class

 

How the class is called.

Public printarg As New ClsPrintArgs(0, "")

 

Using your example

       Dim clstest As Label_Printer.ClsPrintArgs
       MsgBox(clstext.serial)

 

Unfortunately it doesnt like the msgbox's contents. Could you tell me what i am doing wrong pls?

 

Thanks again.

[stustarz]

Could this be a spelling error? :

 

       Dim clstest As Label_Printer.ClsPrintArgs
       'Should this read: MsgBox(clstest.serial) ??
       MsgBox(clstext.serial) 

[stustarz]

Oh! and make the public variables in your class Public Shared

[Jay1b]

Thanks.........How small do i feel now? :)

 

Errr......still getting an error though:

'Object reference not set to an instance of an object'

 

Surely as i can have several references to the same object, this wouldnt be able to determine between them.

[stustarz]

Sorry you may not have seen my latest update: About making the variables declared in your class Public Shared, i have just run the code and everything is fine :)

 

Stu

[Jay1b]

Nope, i didnt see it :)

 

Thank you very much for your help. I assume shared means that all the instances of this class access the same variables?

 

What if i had two instances of a class, with different variables? How could i do that?

 

Thanks again.

[Joe Mamma]

yeah, you wouldnt want them shared

[Jay1b]

In which case, how would you do it?

[PlausiblyDamp]

You would just need to declarte an instance of the class before using it

Dim clstest As new Label_Printer.ClsPrintArgs
MessageBox.Show(clstest.serial.ToString())