c# print barcode font Understanding the Anatomy of an Error in Objective-C

Insert QR in Objective-C Understanding the Anatomy of an Error

private string text; } class Test { public static void Main() { TextObject text = new TextObject("Hello"); IScalable scalable = (IScalable) text; scalable.ScaleX(0.5F); scalable.ScaleY(0.5F); } } This code implements a system for drawing diagrams. All the objects derive from DiagramObject, so they can implement common virtual functions (not shown in this example). Some of the objects can be scaled, and this is expressed by the presence of an implementation of the IScalable interface. Listing the interface name with the base class name for TextObject indicates that TextObject implements the interface. This means TextObject must have functions that match every function in the interface. Interface members have no access modifiers, and the class members that implement the interface members must be publicly accessible. When an object implements an interface, a reference to the interface can be obtained by casting to the interface. This can then be used to call the functions on the interface. This example could have been done with abstract methods, by moving the ScaleX() and ScaleY() methods to DiagramObject and making them virtual. The Design Guidelines section later in this chapter discusses when to use an abstract method and when to use an interface.

Figure 4.10 Pixie displays regions of the screen at various magnification levels and is useful for checking your program's interface layout.

Figure 3.4 The Report Server will use one of the supported data extensions to communicate with the data provider.