Aspen Touch Solutions ATM-123R Series Specifikace stáhnout pdf (Strana 18)

2-4 Objects

2-4

tread type or model number.

2.2.1 Object Hierarchy

The path that is followed to get to a specific property may

involve several objects. The path and structure of objects is

referred to as the object hierarchy. In Visual Basic the properties

and methods of an object are accessed by hooking together the

appropriate objects through a dot operator (.) function. Each dot

operator in the object hierarchy is a function call. In many cases

it is beneficial to reduce the number of calls by setting

intermediate object variables.

For instance, expanding on our previous example involving the

car, suppose there existed an object called Car and you wanted

to set the value of its engine size. You could approach the

problem in one of two ways.

If the Engine size is a property you wanted to access quite often

in your code, using the indirect method of specification may be

easier as it reduces the amount of code thereby reducing the

possibility of error.

2.2.2 HYSYS Type Library

In order to do anything with objects it is first necessary to know

what objects are available. When an application is exposed for

Automation, a separate file is usually created that lists all the

objects and their respective properties and methods. This file is

called the type library and nearly all programs that support

Automation have one of these files available. With the help of an

Object Browser, such as the one built in to MS Excel, you now

have a way to view all the objects, properties, and methods in

Direct specification of object property

Car.Engine.Size = 4

Indirect specification of object property

Dim Eng1 as Object

Set Eng1 = Car.Engine.Size

Eng1 = 4

1 2 ... 13 14 15 16 17 18 19 20 21 22 23 ... 373 374

Žádné komentáře

Aspen Touch Solutions ATM-123R Series Specifikace Strana 18