COM collections are a way to support groups
of related COM objects that can be iterated over. A collection is
itself an interface with
Count property and an
Item method to
retrieve a single item from the collection.
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 string 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
represented by a MATLAB® COM object called
hPlot). In particular, this example iterates
through a collection of
Plot interfaces, invokes
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);