Printers class

A Printers object is a read-only collection of every printer installed on the system. It is exposed through the implicit Printers global --- there is no user-callable constructor --- and yields a Printer for each device, keyed by its DeviceName. Use it to enumerate the installed devices, or to switch the active printer with Set Printer = Printers(name).

Dim p As Printer
For Each p In Printers
    Debug.Print p.DeviceName, p.DriverName, p.Port
Next

Set Printer = Printers("HP LaserJet")    ' make this the active printer

What the collection contains

Each entry is a Printer bound to the corresponding device. These instances are immutable descriptors --- they are intended for identification and for handing to Set Printer = …, not for running a print job directly. Assigning any of the settings properties on one raises run-time error 383 (Property is read-only); calling EndDoc, KillDoc, NewPage, Print, or the other document-control methods raises run-time error 438 (Object doesn't support this property or method). TrackDefault is always False on these instances.

A driver that advertises a single device over multiple ports produces one Printer entry per port; only the first such entry is keyed by DeviceName, the rest are accessible only by numeric index.

Live enumeration

The collection is not cached. Every call to Count, Item, or For Each re-reads the system's installed-printers list from the Windows registry's profile section and reconstructs a fresh batch of Printer instances. A printer added or removed in Settings → Printers therefore appears the next time the collection is touched, with no need to refresh anything from code. The trade-off is that consecutive accesses are not cheap --- when enumerating, cache the result if many lookups are needed:

Dim snapshot As Variant : snapshot = Array()      ' or use a Collection
For Each p In Printers
    snapshot = Array(snapshot, p.DeviceName)      ' (illustrative)
Next

Indexing

Numeric indexing is 0-based, in contrast with most VB6 collections, which are 1-based. The first installed printer is Printers(0); the last is Printers(Printers.Count - 1). An index outside that range raises run-time error 9 (Subscript out of range).

String indexing looks up by DeviceName --- new in twinBASIC; VB6's Printers supports only numeric access. A name that is not present raises the underlying collection's run-time error 5 (Invalid procedure call or argument).

Properties

Count

The number of installed printer entries. Long, read-only. Re-counted on every access --- see Live enumeration.

Syntax: object.Count

Item

Returns the Printer at the given index. Default property --- Printers(0) is shorthand for Printers.Item(0).

Syntax: object.Item( Index ) As Printer

Index

required A Variant. As a Long, the zero-based position in the collection (0 to Count - 1); out-of-range values raise run-time error 9. As a String, the DeviceName of the printer; an unknown name raises run-time error 5.

See Also

• Printer -- the printer object itself, and the implicit Printer global.