COM Object Properties
MATLAB Functions for Object Properties
You can get the value of a property and, sometimes, change the value. You also can add custom properties.
Property names are not case-sensitive. You can abbreviate them as long as the name is unambiguous.
List one or more properties and their values.
Set the value of one or more properties.
Determine if an item is a property of a COM object.
Add a custom property to a COM object.
Remove a custom property from a COM object.
Open the Property Inspector to display and modify property values.
Display the built-in property page of the control, if any.
Work with Multiple Objects
You can use the
set functions on
more than one object at a time by creating a vector of object handles and using
these commands on the vector. To get or set values for multiple objects, use the
functional form of the
functions. Use dot notation, for example
h.propname, on scalar
Enumerated Values for Properties
Enumeration makes examining and changing properties easier because each possible
value for the property is assigned text to represent it. For example, one of the
values for the
DefaultSaveFormat property in a Microsoft®
Excel® spreadsheet is
xlUnicodeText. This text is easier
to remember than a numeric value like 57.
The Property Inspector enables you to access the properties of COM objects. To
open the Property Inspector, use the
inspect function from the
MATLAB® command line or double-click the object in the MATLAB Workspace browser.
For example, create an Excel object. Then set the
DefaultFilePath property to
an existing folder,
h = actxserver('Excel.Application'); h.DefaultFilePath = 'C:\ExcelWork';
Display the properties of the object.
Scroll down until you see the
DefaultFilePath property that
you just changed,
Using the Property Inspector, change
DefaultFilePath once more,
this time to another existing folder,
MyWorkDirectory. To do
this, select the value at the right and type the new value.
Now go back to the MATLAB Command Window and confirm that the
DefaultFilePath property has changed as expected.
ans = C:\MyWorkDirectory
If you modify properties at the MATLAB command line, refresh the Property Inspector window to see the
change reflected there. Refresh the Property Inspector window by reinvoking the
inspect function on the object.
A list button next to a property value indicates that the property accepts
enumerated values. To see the values, click anywhere in the field on the right.
For example, the
Cursor property has four enumerated
values. The current value
xlDefault is displayed in the field
next to the property name.
To change the value, use the list button to display the options for that property, and then click the desired value.
You can add your own properties to an instance of a control using the
To remove custom properties from a control, use the
Properties That Take Arguments
Some COM objects have properties that accept input arguments. Internally,
MATLAB handles these properties as methods, which means you use the
invoke functions (not the
get function) to view the property.