Constructor
From Real Software Documentation
Fires automatically when an object is instantiated.
Syntax
Constructor [parameter list]
| Part | Type | Description |
|---|---|---|
| Parameter List | Any | Optional list of parameters. |
Notes
When you create a new object, you will sometimes want to perform some sort of initialization on the object. The constructor is a mechanism for doing this. A class’s constructor is the method that will be executed automatically when an instance of the class is created.
You write a constructor for a custom class by creating a new method for the class and naming it “Constructor”. The drop-down list for the Method name field suggests this name and the names of all other methods that can be overridden.
When you create a constructor for any subclass, the Real Studio Code Editor automatically inserts code that calls the constructor for its super class using the Super keyword. If there is more than one constructor, it inserts calls to all of them. This is because the subclass’s constructor overrides its super class’s constructor but the new subclass may not initialize itself correctly without a call to the super class’s constructor. You can edit the inserted calls in the event that this assumption is incorrect.
See the chapter on custom classes in the User's Guide for more information on writing constructors. Classes that have constructors have a section that uses the syntax for each constructor.
Examples
This example creates a Date object and sets it to 15 April, 2011.
The following code is from the example project “Custom Drag” in the Examples folder. The main window consists of a Label control and a TextArea. The user can drag the text in the Label into the TextArea. This is not possible by default but the ability to drag the text is enabled by the code in the MouseDown event of the Label. It is:
The following example creates a new FolderItem. You can create a copy of a FolderItem by passing the FolderItem to be copied to the constructor. The result is a copy of the passed FolderItem rather than a reference to it.
The following example creates a new Picture instance that has an alpha channel (i.e., a transparency parameter).
dim height as integer = 2000
// creates new picture
dim pic as new Picture(width, height)
This constructor creates a Picture object that will mirror the content that is drawn into a Canvas in its Paint event.
For example:
See Also
Destructor method; Super keyword.
