It doesn’t convert it from one class to another.
#Steelcase leap office chairs code#
Casting just tells your code to treat the object as a instance of the class to which it is cast. The instance that you are casting has to be of the type that you specify. When you cast an instance, compile-time error-checking cannot guarantee that you are casting to a legal object type. You cast an object by using the classname as a function that operates on the instance. With the IsA operator, you test whether an object is of a specific subclass and, if it is, cast it as that type to do something specific with it. Since the objects you create are subclasses of base classes, you can always test to see whether an object is a member of a specific subclass. The idea is best illustrated by an example. Set the attribute value to the name of an event definition on the class (be sure to enclose the name with quotes).Īn extremely powerful way of creating generic, reusable code is to take advantage of the ability to convert an instance of a class to an instance of its subclass.
HideFromLibrary: The project item will not be shown in the Library's Project Controls section.Hidden: The Hidden attribute hides the specified item from introspection, the debugger and auto-complete.A deprecated item appears in the Errors Panel when you use Analyze Project. Set the attribute value to the name of the class/method/property that should be used instead (be sure to enclose the name with quotes). Deprecated: The Deprecated attribute allows you to indicate that an item “has a replacement” that should instead be used.These attributes may be useful on frameworks you create for use by other developers. There are several reserved attributes that perform special actions when used on a project item (such as a class or module) or a method, property (or constant, etc.) that you can add to the item. GetAttributesįor i As Integer = 0 To myAttributes. This code gets the attribute values of the default window and displays them in a List Box: The AttributeInfo class is used to fetch the Name-Value attribute pairs for a particular object. If you forget the quotes for a literal value, you will get a compiler error if the constant is not found.Īttributes are accessed in your code using Introspection. If it is a constant, you can just use the name of the constant, for example kID. If it is a literal value, such as “ID”, then the value must be enclosed in quotes. Specify the Name and Value for the attribute in the list. Use the “+” or “-” buttons to add or remove attributes. You create an attribute using the Attribute Editor in the advanced tab of the Inspector for the item. These inherited values can be overridden by the subclass by simply redefining them. A subclass inherits attributes from its super class. Attributes can be added to classes, modules, windows, containers, interfaces and toolbars. The Name is required, but the value is optional.Īttributes are added using the advanced tab of the Inspector. An attribute consists of its Name and its Value. They can be added to project items and code items such as method and properties. UserName // Not an actual property, but calls Operator_LookupĪttributes are compile-time properties. Your code to save a value might look like this: The value that is assigned can then be stored (perhaps using a Dictionary). With operator lookup, you use the method to check what was typed after the "." and have that be the name of the preference. If you find you have a new preference value, you’ll need to go back to the class and add the property before you can use it.īut you could use operator lookup instead. Normally, you would have to create a property for each preference you want to save. Suppose you are creating a Preferences class that will be used to save your application preferences. One use for this feature is to look up a value that may not be known until run-time.
Operator Lookup is a special class method that is called when anything following the "." that is not an actual method or property of the class is used. If you try to access a method or property that does not exist, you get a compilation error. TotalAmount Thenįor more information about operator overloading for custom classes, refer to Operator Overloading in the Language Reference.ĭot notation is used to access methods and properties of a class instance. Sub Operator_Compare(rightOrder As SalesOrder)
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