Cool VB FAQ

Text Format

The best Visual Basic FAQ(Frequently Asked Quesitions) file on the internet. Do you have a problem that's got you stumped? Do you have the answer to one? We've done our best to make this the best resources for the questions and the answers. Post a question, or a answer to one, by sending email to VBQA@beadsandbaubles.com.

Root

Classes(Object-Oriented Programming)

   Medium How can I pass multiple parameters to a property let procedure?

   Medium How can I create a class member that is public to other files in my project but private to the world?

   Expert How can I create a stack class with the least amount of code?

How can I pass multiple parameters to a property let procedure?
Let's say I've two (2) string member variables defined as follows:
Private m_s1 As String Private m_s2 As String
I want to create a procedure to "set" these variables in the "TheClass" class and so I code
Public Property Let SetVals(ByVal sStr1 As String, ByVal sStr2 As String) m_s1 = sStr1 m_s2 = sStr2 End Property
In the General Declaration on my form I code
Dim MyClass as TheClass
During Form Load I code
Set MyClass = New TheClass MyClass.SetVals ("AA","BB") ' And god knows how many variations!! . .
No matter what variation on MyClass.SetVals I use (= sign, (), etc.) I get either compilation or run-time errors.

Compatibility:VB3 VB4 VB5

You *can* do this, but not the way you think. It works like this:

            SetVals("AA") = "BB"

It's kind of odd, because the first param is what is on the left side of the assignment(=), and the rest are contained in the params. Like this:

            SetVals(Param2,Param3,Param4) = Param1

However, I would implement your class like this:

      Private m_s1 As String
      Private m_s2 As String
      Property Let  s1(ByVal sStr1 As String)
          m_s1 = sStr1
      End Property

      Property Let  s2(ByVal sStr1 As String)
          m_s2 = sStr1
      End Property

How can I create a class member that is public to other files in my project but private to the world?

Compatibility:VB3 VB4 VB5

Use the Friend keyword.

How can I create a stack class with the least amount of code?

Compatibility:VB3 VB4 VB5

Try this code:

Dim m_Collect As New Collection

Property Get Count() As Long
  Count = m_Collect.Count
End Property
Public Sub Push(i As Variant)
  m_Collect.Add i
End Sub

Public Function Pop() As Variant
  If m_Collect.Count = 0 Then Beep: GoTo exiter
  Pop = m_Collect(m_Collect.Count)
  m_Collect.Remove m_Collect.Count
exiter:
End Function

LinkExchange Member Free Home Pages at GeoCities