COM collections are a way to support groups
of related COM objects that can be iterated over. A collection is
itself an interface with a read-only Count property
and an Item method to retrieve a single item from
the collection.
The Item method is indexed, which means that
it requires an argument that specifies which item in the collection
is being requested. The data type of the index is a data type specified
by the control or server that supports the collection. Although integer
indices are common, the index could also be a text value. Often, the
return value from the Item method is itself an
interface. Like all interfaces, release this interface when you are
finished with it.
This example iterates through the members of a collection. Each
member of the collection is itself an interface (called Plot and
represented by a MATLAB® COM object called hPlot).
In particular, this example iterates through a collection of Plot interfaces,
invokes the Redraw method for each interface, and
then releases each interface:
hCollection = hControl.Plots; for i = 1:hCollection.Count hPlot = invoke(hCollection,'Item', i); Redraw(hPlot) release(hPlot); end; release(hCollection);