Page 332 - Microsoft Office Excel 2003 Programming Inside Out

Microsoft Office Excel 2003 Programming Inside Out

For example, the following line defines a simple property:

Public ProductId As Long

Warning Simple properties can’t be used to return an array, a fixed-length string, a con­
stant, or a complex structure created with a Type statement. If you need a property that
returns any of these things, create the appropriate private class-level variable and then cre­
ate a property routine that performs the same action. For example, you can create a prop­
erty routine that accepts a series of parameters that allow the routine to look like an array.
Likewise, you can create a property routine that accepts and returns fixed-length strings or
complex structures.

Chapter 14
Defining Property Routines

There are three different property routines: Get, Set, and Let. The Property Get routine always
returns a value. Here’s a simple example that references a private class-level variable named
TheProductName.

Public Property Get ProductName As String
ProductName = TheProductName

End Property
The Property Let and Property Set routines are called to save a value into the property. The
Property Let statement is used when the property is a normal variable, whereas the Property
Set statement is used when the property is an object.
The corresponding Property Let routine for the ProductName property would look like this:

Public Property Let ProductName(value As String)

TheProductName = value
End Property

Note The only difference between a Property Set statement and a Property Let statement
is that you use a Property Set statement whenever you are dealing with objects, whereas
you would normally assign values using the Set statement. Likewise, you would use the
Property Let statement whenever you are returning any other value.

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Part 4: Advanced VBA