UIImage Constructors

Definition

Overloads

UIImage()

Default constructor that initializes a new instance of this class with no parameters.

UIImage(CIImage, nfloat, UIImageOrientation)

Constructs a new UIImage backed by the , scaled and oriented as specified.

UIImage(CGImage, nfloat, UIImageOrientation)
UIImage(String)

Creates a UIImage by loading from the provided file name.

UIImage(IntPtr)

A constructor used when creating managed representations of unmanaged objects; Called by the runtime.

UIImage(NSData, nfloat)

Constructs a UIImage from the provided data, scaled by the scale factor.

UIImage(NSData)

Creates a new UIImage from the provided image data.

UIImage(NSCoder)

A constructor that initializes the object from the data stored in the unarchiver object.

UIImage(CIImage)

Creates a new UIImage from the provided Core Image image.

UIImage(CGImage)

Creates a new UIImage from the provided Core Graphics image.

UIImage(NSObjectFlag)

Constructor to call on derived classes to skip initialization and merely allocate the object.

UIImage()

Default constructor that initializes a new instance of this class with no parameters.

[Foundation.Export("init")]
public UIImage ();
Attributes

Remarks

This can be used from a background thread.

UIImage(CIImage, nfloat, UIImageOrientation)

Constructs a new UIImage backed by the , scaled and oriented as specified.

[Foundation.Export("initWithCIImage:scale:orientation:")]
[ObjCRuntime.Introduced(ObjCRuntime.PlatformName.iOS, 6, 0, ObjCRuntime.PlatformArchitecture.All, null)]
[ObjCRuntime.ThreadSafe]
public UIImage (CoreImage.CIImage ciImage, nfloat scale, UIKit.UIImageOrientation orientation);
new UIKit.UIImage : CoreImage.CIImage * nfloat * UIKit.UIImageOrientation -> UIKit.UIImage

Parameters

ciImage
CIImage
scale
nfloat
orientation
UIImageOrientation
Attributes

Remarks

(More documentation for this node is coming)

This can be used from a background thread.

UIImage(CGImage, nfloat, UIImageOrientation)

[Foundation.Export("initWithCGImage:scale:orientation:")]
[ObjCRuntime.ThreadSafe]
public UIImage (CoreGraphics.CGImage cgImage, nfloat scale, UIKit.UIImageOrientation orientation);
new UIKit.UIImage : CoreGraphics.CGImage * nfloat * UIKit.UIImageOrientation -> UIKit.UIImage

Parameters

cgImage
CGImage
scale
nfloat
orientation
UIImageOrientation
Attributes

Remarks

(More documentation for this node is coming)

This can be used from a background thread.

UIImage(String)

Creates a UIImage by loading from the provided file name.

[Foundation.Export("initWithContentsOfFile:")]
[ObjCRuntime.ThreadSafe]
public UIImage (string filename);
new UIKit.UIImage : string -> UIKit.UIImage

Parameters

filename
String

The path to a supported image file.

Attributes

Remarks

The image will not be cached.

This can be used from a background thread.

UIImage(IntPtr)

A constructor used when creating managed representations of unmanaged objects; Called by the runtime.

protected internal UIImage (IntPtr handle);
new UIKit.UIImage : nativeint -> UIKit.UIImage

Parameters

handle
IntPtr

Pointer (handle) to the unmanaged object.

Remarks

This constructor is invoked by the runtime infrastructure (GetNSObject(IntPtr)) to create a new managed representation for a pointer to an unmanaged Objective-C object. Developers should not invoke this method directly, instead they should call the GetNSObject method as it will prevent two instances of a managed object to point to the same native object.

UIImage(NSData, nfloat)

Constructs a UIImage from the provided data, scaled by the scale factor.

[Foundation.Export("initWithData:scale:")]
[ObjCRuntime.Introduced(ObjCRuntime.PlatformName.iOS, 6, 0, ObjCRuntime.PlatformArchitecture.All, null)]
[ObjCRuntime.ThreadSafe]
public UIImage (Foundation.NSData data, nfloat scale);
new UIKit.UIImage : Foundation.NSData * nfloat -> UIKit.UIImage

Parameters

data
NSData

Image data from a file or data that you programmatically create.

scale
nfloat

A size of 1.0 produces an image that is full-size relative to the data.

Attributes

Remarks

(More documentation for this node is coming)

This can be used from a background thread.

UIImage(NSData)

Creates a new UIImage from the provided image data.

[Foundation.Export("initWithData:")]
[ObjCRuntime.ThreadSafe]
public UIImage (Foundation.NSData data);
new UIKit.UIImage : Foundation.NSData -> UIKit.UIImage

Parameters

data
NSData

The NSData object containing the image data.

Attributes

Remarks

The NSData object must match one of the supported image types.

This can be used from a background thread.

UIImage(NSCoder)

A constructor that initializes the object from the data stored in the unarchiver object.

[Foundation.Export("initWithCoder:")]
[ObjCRuntime.DesignatedInitializer]
public UIImage (Foundation.NSCoder coder);
new UIKit.UIImage : Foundation.NSCoder -> UIKit.UIImage

Parameters

coder
NSCoder

The unarchiver object.

Attributes

Remarks

This constructor is provided to allow the class to be initialized from an unarchiver (for example, during NIB deserialization). This is part of the NSCoding protocol.

If developers want to create a subclass of this object and continue to support deserialization from an archive, they should implement a constructor with an identical signature: taking a single parameter of type NSCoder and decorate it with the [Export("initWithCoder:"] attribute declaration.

The state of this object can also be serialized by using the companion method, EncodeTo.

UIImage(CIImage)

Creates a new UIImage from the provided Core Image image.

[Foundation.Export("initWithCIImage:")]
[ObjCRuntime.ThreadSafe]
public UIImage (CoreImage.CIImage ciImage);
new UIKit.UIImage : CoreImage.CIImage -> UIKit.UIImage

Parameters

ciImage
CIImage

A CIImage object.

Attributes

Remarks

This can be used from a background thread.

UIImage(CGImage)

Creates a new UIImage from the provided Core Graphics image.

[Foundation.Export("initWithCGImage:")]
[ObjCRuntime.ThreadSafe]
public UIImage (CoreGraphics.CGImage cgImage);
new UIKit.UIImage : CoreGraphics.CGImage -> UIKit.UIImage

Parameters

cgImage
CGImage

A CGImage object.

Attributes

Remarks

This can be used from a background thread.

UIImage(NSObjectFlag)

Constructor to call on derived classes to skip initialization and merely allocate the object.

protected UIImage (Foundation.NSObjectFlag t);
new UIKit.UIImage : Foundation.NSObjectFlag -> UIKit.UIImage

Parameters

t
NSObjectFlag

Unused sentinel value, pass NSObjectFlag.Empty.

Remarks

This constructor should be called by derived classes when they completely construct the object in managed code and merely want the runtime to allocate and initialize the NSObject. This is required to implement the two-step initialization process that Objective-C uses, the first step is to perform the object allocation, the second step is to initialize the object. When developers invoke the constructor that takes the NSObjectFlag.Empty they take advantage of a direct path that goes all the way up to NSObject to merely allocate the object's memory and bind the Objective-C and C# objects together. The actual initialization of the object is up to the developer.

This constructor is typically used by the binding generator to allocate the object, but prevent the actual initialization to take place. Once the allocation has taken place, the constructor has to initialize the object. With constructors generated by the binding generator this means that it manually invokes one of the "init" methods to initialize the object.

It is the developer's responsibility to completely initialize the object if they chain up using the NSObjectFlag.Empty path.

In general, if the developer's constructor invokes the NSObjectFlag.Empty base implementation, then it should be calling an Objective-C init method. If this is not the case, developers should instead chain to the proper constructor in their class.

The argument value is ignored and merely ensures that the only code that is executed is the construction phase is the basic NSObject allocation and runtime type registration. Typically the chaining would look like this:


//
// The NSObjectFlag merely allocates the object and registers the
// C# class with the Objective-C runtime if necessary, but no actual
// initXxx method is invoked, that is done later in the constructor
//
// This is taken from Xamarin.iOS's source code:
//
[Export ("initWithFrame:")]
public UIView (System.Drawing.RectangleF frame) : base (NSObjectFlag.Empty)
{
// Invoke the init method now.
	var initWithFrame = new Selector ("initWithFrame:").Handle;
	if (IsDirectBinding)
		Handle = ObjCRuntime.Messaging.IntPtr_objc_msgSend_CGRect (this.Handle, initWithFrame, frame);
	else
		Handle = ObjCRuntime.Messaging.IntPtr_objc_msgSendSuper_CGRect (this.SuperHandle, initWithFrame, frame);
}

Applies to