UIDevice Class Reference

Properties

For more about Objective-C properties, see “Properties” in The Objective-C Programming Language.

batteryLevel

The battery charge level for the device.

@property (nonatomic,readonly) float batteryLevel

Discussion

Battery level ranges from 0.0 (fully discharged) to 1.0 (100% charged). Before accessing this property, ensure that battery monitoring is enabled.

If battery monitoring is not enabled, battery state is UIDeviceBatteryStateUnknown and the value of this property is –1.0.

See Also

•   @property batteryState
•   @property batteryMonitoringEnabled

batteryMonitoringEnabled

A Boolean value indicating whether battery monitoring is enabled (YES) or not (NO).

@property (nonatomic,getter=isBatteryMonitoringEnabled) BOOL batteryMonitoringEnabled

Discussion

Enable battery monitoring only when your application needs to be notified of changes to the battery state. Otherwise, disable battery monitoring. The default value is NO.

See Also

•   @property batteryLevel
•   @property batteryState

batteryState

The battery state for the device.

@property (nonatomic,readonly) UIDeviceBatteryState batteryState

Discussion

The value for batteryState is one of the constants in “UIDeviceBatteryState.”

If battery monitoring is not enabled, the value of this property is UIDeviceBatteryStateUnknown.

See Also

•   @property batteryLevel
•   @property batteryMonitoringEnabled

generatesDeviceOrientationNotifications

A Boolean value that indicates whether the receiver generates orientation notifications (YES) or not (NO). (read-only)

@property (nonatomic, readonly, getter=isGeneratingDeviceOrientationNotifications) BOOL generatesDeviceOrientationNotifications

Discussion

If the value of this property is YES, the shared UIDevice object posts a UIDeviceOrientationDidChangeNotification notification when the device changes orientation. If the value is NO, it generates no orientation notifications. Device orientation notifications can only be generated between calls to the beginGeneratingDeviceOrientationNotifications and endGeneratingDeviceOrientationNotifications methods.

See Also

• – beginGeneratingDeviceOrientationNotifications
• – endGeneratingDeviceOrientationNotifications

localizedModel

The model of the device as a localized string. (read-only)

@property (nonatomic, readonly, retain) NSString *localizedModel

Discussion

This string would be a localized version of the string returned from model.

model

The model of the device. (read-only)

@property (nonatomic, readonly, retain) NSString *model

Discussion

Possible examples of model strings are @”iPhone” and @”iPod touch”.

name

The name identifying the device. (read-only)

@property (nonatomic, readonly, retain) NSString *name

Discussion

The value of this property is an arbitrary string that is associated with the device as an identifier. For example, you can find the name of an iPhone in the General > About settings.

See Also

•   @property systemName

Related Sample Code

• CryptoExercise

orientation

Returns the physical orientation of the device. (read-only)

@property (nonatomic, readonly) UIDeviceOrientation orientation

Discussion

The value of the property is a constant that indicates the current orientation of the device. This value represents the physical orientation of the device and may be different from the current orientation of your application’s user interface. See “UIDeviceOrientation” for descriptions of the possible values.

The value of this property always returns 0 unless orientation notifications have been enabled by calling beginGeneratingDeviceOrientationNotifications.

See Also

•   @property generatesDeviceOrientationNotifications
• – beginGeneratingDeviceOrientationNotifications

proximityMonitoringEnabled

A Boolean value indicating whether proximity monitoring is enabled (YES) or not (NO).

@property (nonatomic,getter=isProximityMonitoringEnabled) BOOL proximityMonitoringEnabled

Discussion

Enable proximity monitoring only when your application needs to be notified of changes to the proximity state. Otherwise, disable proximity monitoring. The default value is NO.

Not all iPhone OS devices have proximity sensors. To determine if proximity monitoring is available, attempt to enable it. If the value of the proximityState property remains NO, proximity monitoring is not available.

See Also

•   @property proximityState

proximityState

A Boolean value indicating whether the proximity sensor is close to the user (YES) or not (NO).

@property (nonatomic,readonly) BOOL proximityState

See Also

•   @property proximityMonitoringEnabled

systemName

The name of the operating system running on the device represented by the receiver. (read-only)

@property (nonatomic, readonly, retain) NSString *systemName

See Also

•   @property name
•   @property systemVersion

systemVersion

The current version of the operating system. (read-only)

@property (nonatomic, readonly, retain) NSString *systemVersion

Discussion

An example of the system version is @”1.2”.

See Also

•   @property systemName

Related Sample Code

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uniqueIdentifier

A string unique to each device based on various hardware details. (read-only)

@property (nonatomic, readonly, retain) NSString *uniqueIdentifier

Discussion

A unique device identifier is a hash value composed from various hardware identifiers such as the device’s serial number. It is guaranteed to be unique for every device but cannot publically be tied to a user account. You can use it, for example, to store high scores for a game in a central server or to control access to registered products. The unique device identifier is sometimes referred to by its abbreviation UDID.

Related Sample Code

• GKTank

Class Methods

currentDevice

Returns an object representing the current device.

+ (UIDevice *)currentDevice

Discussion

You access the properties of the returned UIDevice instance to obtain information about the device. You must instantiate the UIDevice instance before registering to receive device notifications.

Related Sample Code

• AlternateViews
• BatteryStatus
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typedef enum {
   UIDeviceBatteryStateUnknown,
   UIDeviceBatteryStateUnplugged,
   UIDeviceBatteryStateCharging,
   UIDeviceBatteryStateFull,
} UIDeviceBatteryState;

typedef enum {
   UIDeviceOrientationUnknown,
   UIDeviceOrientationPortrait,
   UIDeviceOrientationPortraitUpsideDown,
   UIDeviceOrientationLandscapeLeft,
   UIDeviceOrientationLandscapeRight,
   UIDeviceOrientationFaceUp,
   UIDeviceOrientationFaceDown
} UIDeviceOrientation;

Notifications

All UIDevice notifications are posted by the singleton device instance returned by currentDevice.

UIDeviceBatteryLevelDidChangeNotification

Posted when the battery level changes.

Notifications for battery level change are sent no more frequently than once per minute. Do not attempt to calculate battery drainage rate or battery time remaining; drainage rate can change frequently depending on built-in applications as well as your application.

You can obtain the battery level by getting the value of the batteryLevel property.

UIDeviceBatteryStateDidChangeNotification

Posted when battery state changes.

You can obtain the battery state by getting the value of the batteryState property.

UIDeviceOrientationDidChangeNotification

Posted when the orientation of the device changes.

You can obtain the new orientation by getting the value of the orientation property.

UIDeviceProximityStateDidChangeNotification

Posted when the state of the proximity sensor changes.

You can obtain the proximity state by getting the value of the proximityState property.