UIKit Constants Reference

Overview

This document describes constants that are used throughout the UIKit framework.

Constants

UIEdgeInsetsZero

Defines a set of edge insets where all of the values are 0.

extern const UIEdgeInsets UIEdgeInsetsZero;

Constants

UIEdgeInsetsZero

A UIEdgeInsets struct whose top, left, bottom, and right fields are all set to the value 0.

Available in iOS 2.0 and later.

Declared in UIGeometry.h.

UIOffsetZero

Defines an offset where all of the values are 0.

extern const UIOffset UIOffsetZero;

Constants

UIOffsetZero

A UIOffset struct whose horizontal and vertical fields are set to the value 0.

Available in iOS 5.0 and later.

Declared in UIGeometry.h.

Interface Builder Constants

Type qualifiers used by Interface Builder to synchronize with Xcode.

#define IBAction void
#define IBOutlet
#define IBOutletCollection(ClassName)

Constants

IBAction

Type qualifier used by Interface Builder to synchronize actions. Use this type as the return type of any action methods defined in your project. For examples of how to use this identifier, see “Xcode Integration”.

Available in iOS 2.0 and later.

Declared in UINibDeclarations.h.

IBOutlet

Identifier used to identify a property so Interface Builder can synchronize the display and connection of outlets with Xcode. Insert this identifier immediately before the type in any declarations. For examples, including how to use it with the @property syntax, see “Xcode Integration”.

Available in iOS 2.0 and later.

Declared in UINibDeclarations.h.

IBOutletCollection

Identifier used to qualify a one-to-many instance-variable declaration so that Interface Builder can synchronize the display and connection of outlets with Xcode. You can insert this macro only in front of variables typed as NSArray or NSMutableArray.

This macro takes an optional ClassName parameter. If specified, Interface Builder requires all objects added to the array to be instances of that class. For example, to define a property that stores only UIView objects, you could use a declaration similar to the following:

@property (nonatomic, retain) IBOutletCollection(UIView) NSArray *views;

For additional examples of how to declare outlets, including how to create outlets with the @property syntax, see “Xcode Integration”.

Available in iOS 4.0 and later.

Declared in UINibDeclarations.h.