UIImage Class
Definition
Important
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Image representation in UIKit, with support for loading, saving and manipulating images.
[Foundation.Register("UIImage", true)]
public class UIImage : Foundation.NSObject, Foundation.INSItemProviderReading, Foundation.INSItemProviderWriting, Foundation.INSSecureCoding, IDisposable, UIKit.IUIAccessibilityIdentification, UIKit.IUIItemProviderPresentationSizeProviding
type UIImage = class
inherit NSObject
interface INSCoding
interface INativeObject
interface IDisposable
interface INSItemProviderReading
interface INSItemProviderWriting
interface INSSecureCoding
interface IUIAccessibilityIdentification
interface IUIItemProviderPresentationSizeProviding
- Inheritance
- Attributes
- Implements
Remarks
Image objects do not provide direct access to the underlying image - they are immutable. The methods M:UIKit.UIImage.AsJPEG() or AsPNG() will provide the underlying image data as a JPEG or PNG.
To avoid issues with excessive memory use, UIImages objects should not be larger than 1024x1024 in size. Code-based manipulations such as resizing are not subject to this restriction.
It is possible that the system may purge UIImage objects to free up memory. If the UIImage is required later on by an application, it will be loaded again from its source file.
The following image formats are supported by the UIImage class:
- .tiff:
- .jpg, .jpeg:
- .gif:
- .bmp:
- .ico:
- .cur:
- .xbm:
Starting with iOS 8, the M:UIKIt.UIImage.FromBundle(System.String,Foundation.NSBundle,UIKIt.UITraitCollection) method can be used to load a UIImage that takes into consideration a UITraitCollection. This can automatically load the proper image for the specified resolution.
Most of the members of this class can be used from a background thread, with a couple of exceptions (FromBundle methods that retrieve images from the bundle and use the built-in memory cache).
Constructors
UIImage() |
Default constructor that initializes a new instance of this class with no parameters. |
UIImage(CGImage, nfloat, UIImageOrientation) | |
UIImage(CGImage) |
Creates a new UIImage from the provided Core Graphics image. |
UIImage(CIImage, nfloat, UIImageOrientation) |
Constructs a new UIImage backed by the , scaled and oriented as specified. |
UIImage(CIImage) |
Creates a new UIImage from the provided Core Image image. |
UIImage(IntPtr) |
A constructor used when creating managed representations of unmanaged objects; Called by the runtime. |
UIImage(NSCoder) |
A constructor that initializes the object from the data stored in the unarchiver object. |
UIImage(NSData, nfloat) |
Constructs a UIImage from the provided |
UIImage(NSData) |
Creates a new UIImage from the provided image data. |
UIImage(NSObjectFlag) |
Constructor to call on derived classes to skip initialization and merely allocate the object. |
UIImage(String) |
Creates a UIImage by loading from the provided file name. |
Properties
AccessibilityActivationPoint |
Gets or sets the screen coordinates of the activation point for |
AccessibilityAttributedHint |
Gets or sets the NSAttributedString for the accessibility hint. |
AccessibilityAttributedLabel |
Gets or sets the NSAttributedString used for the accessibility label. |
AccessibilityAttributedValue |
Gets or sets the NSAttributedString used for the accessibility value. |
AccessibilityElementsHidden |
Gets or sets whether accessibility elements contained in |
AccessibilityFrame |
Gets or sets the screen coordinates of the frame of |
AccessibilityHint |
Gets or sets a localized string that describes the result of an action. |
AccessibilityIdentifier |
Gets or sets an identifier that identifies |
AccessibilityLabel |
Gets or sets a localized string to identify |
AccessibilityLanguage |
Gets or sets the language for the AccessibilityLabel, AccessibilityValue, and AccessibilityHint of |
AccessibilityNavigationStyle |
Gets or sets the navigation style. |
AccessibilityPath |
Specifies screen coordinates for the path of an element that is used to highlight the element. |
AccessibilityTraits |
Gets or sets the accessibility traits that best characterize |
AccessibilityValue |
Specifies a localized string that contains the value of |
AccessibilityViewIsModal |
Gets or sets whether VoiceOver ignores elements in sibling views of this image object. |
AlignmentRectInsets |
Alignment metadata that provides hints for aligning the UIImage content. |
AnnouncementDidFinishNotification |
Notification constant for AnnouncementDidFinish |
AnnouncementNotification |
Gets the notification posted by an application that an announcement requires assistive technology. |
AssistiveTechnologyKey |
The string "UIAccessibilityAssistiveTechnologyKey" which can be used to distinguish accessibility notifications.. |
AssistiveTouchStatusDidChangeNotification |
Notification constant for AssistiveTouchStatusDidChange |
BoldTextStatusDidChangeNotification |
Notification constant for BoldTextStatusDidChange |
CapInsets |
The portions of a image that are not resized when the image is stretched. Read-only. |
CGImage |
The underlying image data. Read-only. |
CIImage |
The underlying CIImage data. Read-only. |
Class | (Inherited from NSObject) |
ClassHandle |
The handle for this class. |
ClosedCaptioningStatusDidChangeNotification |
Notification constant for ClosedCaptioningStatusDidChange |
CurrentScale |
The scale of the image. |
DarkerSystemColorsStatusDidChangeNotification |
Notification constant for DarkerSystemColorsStatusDidChange |
DebugDescription |
A developer-meaningful description of this object. (Inherited from NSObject) |
Description |
Description of the object, the Objective-C version of ToString. (Inherited from NSObject) |
Duration |
The time interval to display the animated image. Read-only. |
ElementFocusedNotification |
Notification constant for ElementFocused |
FlipsForRightToLeftLayoutDirection |
Whether this image is mirrored when layout is right-to-left. |
FocusedElementKey |
A string constant used by accessibility APIs (see FocusedElement(String)) to identify the focused element. |
GrayscaleStatusDidChangeNotification |
Notification constant for GrayscaleStatusDidChange |
GuidedAccessStatusDidChangeNotification |
Notification constant for GuidedAccessStatusDidChange |
Handle |
Handle (pointer) to the unmanaged object representation. (Inherited from NSObject) |
HearingDevicePairedEarDidChangeNotification |
Notification constant for HearingDevicePairedEarDidChange |
ImageAsset |
Gets an image asset with which the image is associated. |
ImageRendererFormat |
Gets the best UIGraphicsImageRendererFormat for the UIImage. |
Images |
An array of UIImage objects that make up an animated iamge. |
InvertColorsStatusDidChangeNotification |
Notification constant for InvertColorsStatusDidChange |
IsAccessibilityElement |
Gets or sets whether this image is an accessibility object that an assistive app can access. |
IsDirectBinding | (Inherited from NSObject) |
IsProxy | (Inherited from NSObject) |
LayoutChangedNotification |
Gets the notification posted by an application that the layout of a screen has changed. |
LeftCapWidth |
The width of the left cap. |
MonoAudioStatusDidChangeNotification |
Notification constant for MonoAudioStatusDidChange |
NotificationSwitchControlIdentifier |
Notification constant for NotificationSwitchContr |
NotificationVoiceOverIdentifier |
Notification constant for NotificationVoiceOv |
Orientation |
The orienation of the image. Read-only. |
PageScrolledNotification |
Gets the notification posted by an application that a scroll action has finished. |
PauseAssistiveTechnologyNotification |
Pauses assistive technology notifications. |
PreferredPresentationSizeForItemProvider | |
ReadableTypeIdentifiers |
Gets the array of Uniform Type Identifiers (UTIs) for the image. |
ReduceMotionStatusDidChangeNotification |
Notification constant for ReduceMotionStatusDidChange |
ReduceTransparencyStatusDidChangeNotification |
Notification constant for ReduceTransparencyStatusDidChange |
RenderingMode |
The default value is Automatic. |
ResizingMode |
The resizing mode used by the image. |
ResumeAssistiveTechnologyNotification |
Resumes assistive technology notifications. |
RetainCount |
Returns the current Objective-C retain count for the object. (Inherited from NSObject) |
ScreenChangedNotification |
Gets the notification posted by an application that a new view appears that includes a major portion of the screen. |
Self | (Inherited from NSObject) |
ShakeToUndoDidChangeNotification |
Notification constant for ShakeToUndoDidChange |
ShouldGroupAccessibilityChildren |
Gets or sets whether VoiceOver groups elements that are children of this object regardless of their positions. |
Size |
The dimensions of the image. Read-only. |
SpeakScreenStatusDidChangeNotification |
Notification constant for SpeakScreenStatusDidChange |
SpeakSelectionStatusDidChangeNotification |
Notification constant for SpeakSelectionStatusDidChange |
SpeechAttributeIpaNotation |
Returns the IPA notation for the accessibility attributed string. |
SpeechAttributeLanguage |
Gets a BCP-47 language code. |
SpeechAttributePitch |
Gets the value from 0.0 to 2.0 that determines the pitch for a spoken string. |
SpeechAttributePunctuation |
Gets a value to be interpreted as a |
SpeechAttributeQueueAnnouncement |
Key for option that spoken text interrupt existing spoken content. |
Superclass | (Inherited from NSObject) |
SuperHandle |
Handle used to represent the methods in the base class for this NSObject. (Inherited from NSObject) |
SwitchControlStatusDidChangeNotification |
Notification constant for SwitchControlStatusDidChange |
TextAttributeCustom |
Key for option that custom attributes be applied to the accessibility text. |
TextAttributeHeadingLevel |
Key for option of the accessibility text's heading level. |
TopCapHeight |
The height of the top cap (non-resizable area). |
TraitAdjustable |
Gets a trait that allows continuous adjustment of an accessibility element through a range of values. |
TraitAllowsDirectInteraction |
Gets a trait that allows direct touch interaction for users. |
TraitButton |
Gets a trait that indicates that |
TraitCausesPageTurn |
Gets a trait that indicates that |
TraitCollection |
Returns a trait collection. |
TraitHeader |
Gets a trait that indicates that |
TraitImage |
Gets a trait that indicates that |
TraitKeyboardKey |
Gets a trait that indicates that |
TraitLink |
Gets a trait that indicates that |
TraitNone |
Gets a trait that indicates that |
TraitNotEnabled |
Gets a trait that indicates that |
TraitPlaysSound |
Gets a trait that indicates that |
TraitSearchField |
Gets a trait that indicates that |
TraitSelected |
Gets a trait that indicates that |
TraitStartsMediaSession |
Gets a trait that indicates that |
TraitStaticText |
Gets a trait that indicates that |
TraitSummaryElement |
Gets a trait that provides summary information when an application starts. |
TraitTabBar | |
TraitUpdatesFrequently |
Gets a trait that indicates that |
UnfocusedElementKey |
A string constant used by accessibility APIs (see FocusedElement(String)) to identify the previously focused element. |
VoiceOverStatusChanged |
Developers should not use this deprecated property. Developers should use 'VoiceOverStatusDidChangeNotification' instead. |
VoiceOverStatusDidChangeNotification |
Notification constant for VoiceOverStatusDidChange |
WritableTypeIdentifiers |
Gets the array of uniform type identifiers that specify which data types can be loaded into a color. |
WritableTypeIdentifiersForItemProvider |
Gets the array of uniform type identifiers that specify which data types can be loaded into a color. |
Zone | (Inherited from NSObject) |
Methods
AccessibilityActivate() |
Activates accessibility for this UIImage, returning |
AddObserver(NSObject, NSString, NSKeyValueObservingOptions, IntPtr) |
Registers an object for being observed externally (using NSString keyPath). Observed changes are dispatched to the observer’s object ObserveValue(NSString, NSObject, NSDictionary, IntPtr) method. (Inherited from NSObject) |
AddObserver(NSObject, String, NSKeyValueObservingOptions, IntPtr) |
Registers an object for being observed externally (using string keyPath). Observed changes are dispatched to the observer’s object ObserveValue(NSString, NSObject, NSDictionary, IntPtr) method. (Inherited from NSObject) |
AddObserver(NSString, NSKeyValueObservingOptions, Action<NSObservedChange>) |
Registers an object for being observed externally using an arbitrary method. (Inherited from NSObject) |
AddObserver(String, NSKeyValueObservingOptions, Action<NSObservedChange>) |
Registers an object for being observed externally using an arbitrary method. (Inherited from NSObject) |
AsJPEG() |
Encodes the image with minimal compression (maximum quality) into a NSData byte blob using the JPEG encoding. |
AsJPEG(nfloat) |
Encodes the image into a NSData byte blob using the JPEG encoding. |
AsPNG() |
Encodes the image into a NSData byte blob using the PNG encoding. |
AwakeFromNib() |
Called after the object has been loaded from the nib file. Overriders must call base.AwakeFromNib(). (Inherited from NSObject) |
BeginInvokeOnMainThread(Action) | (Inherited from NSObject) |
BeginInvokeOnMainThread(Selector, NSObject) |
Invokes asynchrously the specified code on the main UI thread. (Inherited from NSObject) |
Bind(NSString, NSObject, String, NSDictionary) | (Inherited from NSObject) |
Bind(String, NSObject, String, NSDictionary) |
Obsolete.
(Inherited from NSObject)
|
BindingInfo(String) |
Obsolete.
(Inherited from NSObject)
|
BindingOptionDescriptions(String) |
Obsolete.
(Inherited from NSObject)
|
BindingValueClass(String) |
Obsolete.
(Inherited from NSObject)
|
CommitEditing() | (Inherited from NSObject) |
CommitEditing(NSObject, Selector, IntPtr) | (Inherited from NSObject) |
ConformsToProtocol(IntPtr) |
Invoked to determine if this object implements the specified protocol. (Inherited from NSObject) |
Copy() |
Performs a copy of the underlying Objective-C object. (Inherited from NSObject) |
CreateAnimatedImage(String, Double) |
Creates an animated image from a series of files. |
CreateAnimatedImage(String, UIEdgeInsets, Double) |
Creates a new animated image by loading a set of identically sized and scaled image files that have names that begin with |
CreateAnimatedImage(String, UIEdgeInsets, UIImageResizingMode, Double) |
Factory method to create an animated image with end caps and the specified |
CreateAnimatedImage(UIImage[], Double) |
This method will create a animated image from a collection of images. |
CreateResizableImage(UIEdgeInsets, UIImageResizingMode) |
Creates a new image, based on the current, with the specified |
CreateResizableImage(UIEdgeInsets) |
Creates a new image from the current instance and applies the specified cap insets. |
DangerousAutorelease() | (Inherited from NSObject) |
DangerousRelease() | (Inherited from NSObject) |
DangerousRetain() | (Inherited from NSObject) |
DidChange(NSKeyValueChange, NSIndexSet, NSString) |
Indicates a change occurred to the indexes for a to-many relationship. (Inherited from NSObject) |
DidChange(NSString, NSKeyValueSetMutationKind, NSSet) | (Inherited from NSObject) |
DidChangeValue(String) |
Indicates that a change occurred on the specified key. (Inherited from NSObject) |
Dispose() |
Releases the resources used by the NSObject object. (Inherited from NSObject) |
Dispose(Boolean) |
Releases the resources used by the NSObject object. (Inherited from NSObject) |
DoesNotRecognizeSelector(Selector) |
Indicates that this object does not recognize the specified selector. (Inherited from NSObject) |
Draw(CGPoint, CGBlendMode, nfloat) |
Draws the UIImage into the current graphics context at the specified , with blending mode and alpha as specified. |
Draw(CGPoint) |
Draws the image at the specified position. |
Draw(CGRect, CGBlendMode, nfloat) |
Draws the UIImage into the current graphics context in the specified , with blending mode and alpha as specified. |
Draw(CGRect) |
This method will draw the image (scaling as necessary) in the rectangle specified. |
DrawAsPatternInRect(CGRect) |
This method will draw an image in the specified rectangle. |
EncodeTo(NSCoder) |
Encodes the state of the object on the provided encoder |
Equals(NSObject) | (Inherited from NSObject) |
Equals(Object) | (Inherited from NSObject) |
ExposedBindings() | (Inherited from NSObject) |
FromBundle(String, NSBundle, UITraitCollection) |
Gets an image from the specified bundle that is compatible with the specified trait collection. |
FromBundle(String) |
Loads an image relative to the application bundle, and caches its result. |
FromFile(String) |
Create an image object from the specified file. |
FromImage(CGImage, nfloat, UIImageOrientation) |
Static factory method to create a UIImage backed by the specified , scaled and oriented as specified. |
FromImage(CGImage) |
Creates a new image oject from a Quartz image. |
FromImage(CIImage, nfloat, UIImageOrientation) |
Static factory method to create a UIImage backed by the specified , scaled and oriented as specified. |
FromImage(CIImage) |
Factory method to create a UIImage from a Core Image CIImage. |
FromResource(Assembly, String) |
Loads an image from a resource embedded in the assembly. |
GetBindingInfo(NSString) | (Inherited from NSObject) |
GetBindingOptionDescriptions(NSString) | (Inherited from NSObject) |
GetBindingValueClass(NSString) | (Inherited from NSObject) |
GetDictionaryOfValuesFromKeys(NSString[]) |
Retrieves the values of the specified keys. (Inherited from NSObject) |
GetHashCode() |
Generates a hash code for the current instance. (Inherited from NSObject) |
GetImageFlippedForRightToLeftLayoutDirection() |
Developers can override this method to provide an appropriate image for left-to-right layouts. |
GetImageWithHorizontallyFlippedOrientation() |
Returns a mirror-image copy of this UIImage. |
GetItemProviderVisibilityForTypeIdentifier(String) |
Gets the default representation visibility for the UTI . |
GetMethodForSelector(Selector) | (Inherited from NSObject) |
GetNativeField(String) |
Obsolete.
(Inherited from NSObject)
|
GetNativeHash() | (Inherited from NSObject) |
GetObject(NSData, String, NSError) |
Static factory method to create a UIImage from , with being the appropriate UTI. |
ImageWithAlignmentRectInsets(UIEdgeInsets) |
Creates a UIImage based on |
ImageWithRenderingMode(UIImageRenderingMode) |
Creates a UIImage based on the current one, with the specified |
Init() | (Inherited from NSObject) |
InitializeHandle(IntPtr, String) | (Inherited from NSObject) |
InitializeHandle(IntPtr) | (Inherited from NSObject) |
Invoke(Action, Double) | (Inherited from NSObject) |
Invoke(Action, TimeSpan) | (Inherited from NSObject) |
InvokeOnMainThread(Action) | (Inherited from NSObject) |
InvokeOnMainThread(Selector, NSObject) |
Invokes synchrously the specified code on the main UI thread. (Inherited from NSObject) |
IsEqual(NSObject) | (Inherited from NSObject) |
IsKindOfClass(Class) | (Inherited from NSObject) |
IsMemberOfClass(Class) | (Inherited from NSObject) |
LoadData(String, Action<NSData,NSError>) |
Loads data for the identified type from an item provider. |
LoadDataAsync(String, NSProgress) |
Asynchronously loads data for the identified type from an item provider, returning a task that contains the data, and storing the data in |
LoadDataAsync(String) |
Asynchronously loads data for the identified type from an item provider, returning a task that contains the data. |
LoadFromData(NSData, nfloat) |
Factory method to create a UIImage from the provided |
LoadFromData(NSData) |
Will create an image from data that originated from a file or was programmatically created. |
MarkDirty() |
Promotes a regular peer object (IsDirectBinding is true) into a toggleref object. (Inherited from NSObject) |
MutableCopy() |
Creates a mutable copy of the specified NSObject. (Inherited from NSObject) |
ObjectDidEndEditing(NSObject) | (Inherited from NSObject) |
ObserveValue(NSString, NSObject, NSDictionary, IntPtr) |
Indicates that the value at the specified keyPath relative to this object has changed. (Inherited from NSObject) |
PerformSelector(Selector, NSObject, Double, NSString[]) | (Inherited from NSObject) |
PerformSelector(Selector, NSObject, Double) |
Invokes the selector on the current instance and if the |
PerformSelector(Selector, NSObject, NSObject) | (Inherited from NSObject) |
PerformSelector(Selector, NSObject) | (Inherited from NSObject) |
PerformSelector(Selector, NSThread, NSObject, Boolean, NSString[]) | (Inherited from NSObject) |
PerformSelector(Selector, NSThread, NSObject, Boolean) | (Inherited from NSObject) |
PerformSelector(Selector) | (Inherited from NSObject) |
PrepareForInterfaceBuilder() | (Inherited from NSObject) |
RemoveObserver(NSObject, NSString, IntPtr) |
Stops the specified observer from receiving further notifications of changed values for the specified keyPath and context. (Inherited from NSObject) |
RemoveObserver(NSObject, NSString) |
Stops the specified observer from receiving further notifications of changed values for the specified keyPath. (Inherited from NSObject) |
RemoveObserver(NSObject, String, IntPtr) |
Stops the specified observer from receiving further notifications of changed values for the specified keyPath and context. (Inherited from NSObject) |
RemoveObserver(NSObject, String) |
Stops the specified observer from receiving further notifications of changed values for the specified keyPath. (Inherited from NSObject) |
RespondsToSelector(Selector) |
Whether this object recognizes the specified selector. (Inherited from NSObject) |
SaveToPhotosAlbum(UIImage+SaveStatus) |
Saves the specified image into the Photos Album. |
Scale(CGSize, nfloat) |
Scales the image up or down. |
Scale(CGSize) |
Scales the image up or down. |
SetNativeField(String, NSObject) |
Obsolete.
(Inherited from NSObject)
|
SetNilValueForKey(NSString) |
Sets the value of the specified key to null. (Inherited from NSObject) |
SetValueForKey(NSObject, NSString) |
Sets the value of the property specified by the key to the specified value. (Inherited from NSObject) |
SetValueForKeyPath(IntPtr, NSString) |
A constructor used when creating managed representations of unmanaged objects; Called by the runtime. (Inherited from NSObject) |
SetValueForKeyPath(NSObject, NSString) |
Sets the value of a property that can be reached using a keypath. (Inherited from NSObject) |
SetValueForUndefinedKey(NSObject, NSString) |
Indicates an attempt to write a value to an undefined key. If not overridden, raises an NSUndefinedKeyException. (Inherited from NSObject) |
SetValuesForKeysWithDictionary(NSDictionary) |
Sets the values of this NSObject to those in the specified dictionary. (Inherited from NSObject) |
StretchableImage(nint, nint) |
Creates a stretchable image with the specified parameters. Deprecated in iOS 5, but still useful since the replacement is known to have bugs. |
ToString() |
Returns a string representation of the value of the current instance. (Inherited from NSObject) |
Unbind(NSString) | (Inherited from NSObject) |
Unbind(String) |
Obsolete.
(Inherited from NSObject)
|
ValueForKey(NSString) |
Returns the value of the property associated with the specified key. (Inherited from NSObject) |
ValueForKeyPath(NSString) |
Returns the value of a property that can be reached using a keypath. (Inherited from NSObject) |
ValueForUndefinedKey(NSString) |
Indicates an attempt to read a value of an undefined key. If not overridden, raises an NSUndefinedKeyException. (Inherited from NSObject) |
WillChange(NSKeyValueChange, NSIndexSet, NSString) |
Indicates that the values of the specified indices in the specified key are about to change. (Inherited from NSObject) |
WillChange(NSString, NSKeyValueSetMutationKind, NSSet) | (Inherited from NSObject) |
WillChangeValue(String) |
Indicates that the value of the specified key is about to change. (Inherited from NSObject) |
Extension Methods
GetItemProviderVisibilityForTypeIdentifier(INSItemProviderWriting, String) | |
GetWritableTypeIdentifiersForItemProvider(INSItemProviderWriting) | |
LoadDataAsync(INSItemProviderWriting, String, NSProgress) | |
LoadDataAsync(INSItemProviderWriting, String) | |
GetDebugDescription(INSObjectProtocol) | |
GetAccessibilityCustomRotors(NSObject) |
Gets the array of UIAccessibilityCustomRotor objects appropriate for |
SetAccessibilityCustomRotors(NSObject, UIAccessibilityCustomRotor[]) |
Sets the array of UIAccessibilityCustomRotor objects appropriate for |