ImageExt class

A widget that displays an image.

Several constructors are provided for the various ways that an image can be specified:

• new Image, for obtaining an image from an ImageProvider.
• new Image.asset, for obtaining an image from an AssetBundle using a key.
• new Image.network, for obtaining an image from a URL.
• new Image.file, for obtaining an image from a File.
• new Image.memory, for obtaining an image from a Uint8List.

The following image formats are supported:

To automatically perform pixel-density-aware asset resolution, specify the image using an AssetImage and make sure that a MaterialApp, WidgetsApp, or MediaQuery widget exists above the Image widget in the widget tree.

The image is painted using paintImage, which describes the meanings of the various fields on this class in more detail.

{@tool snippet} The default constructor can be used with any ImageProvider, such as a NetworkImage, to display an image from the internet.

const Image(
  image: NetworkImage('https://flutter.github.io/assets-for-api-docs/assets/widgets/owl.jpg'),
)

{@end-tool}

{@tool snippet} The Image Widget also provides several constructors to display different types of images for convenience. In this example, use the Image.network constructor to display an image from the internet.

Image.network('https://flutter.github.io/assets-for-api-docs/assets/widgets/owl-2.jpg')

{@end-tool}

The Image.asset, Image.network, Image.file, and Image.memory constructors allow a custom decode size to be specified through cacheWidth and cacheHeight parameters. The engine will decode the image to the specified size, which is primarily intended to reduce the memory usage of ImageCache.

In the case where a network image is used on the Web platform, the cacheWidth and cacheHeight parameters are ignored as the Web engine delegates image decoding of network images to the Web, which does not support custom decode sizes.

See also:

• Icon, which shows an image from a font.
• new Ink.image, which is the preferred way to show an image in a material application (especially if the image is in a Material and will have an InkWell on top of it).
• Image, the class in the dart:ui library.
• Cookbook: Display images from the internet
• Cookbook: Work with cached images
• Cookbook: Fade in images with a placeholder

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatefulWidget
• ImageExt

Constructors

ImageExt({Key? key, required ImageProvider<Object> image, CustomImageBuilder? imageBuilder, ImageFrameBuilder? frameBuilder, ImageLoadingBuilder? loadingBuilder, ImageErrorWidgetBuilder? errorBuilder, String? semanticLabel, bool excludeFromSemantics = false, double? width, double? height, Color? color, Animation<double>? opacity, BlendMode? colorBlendMode, BoxFit? fit, AlignmentGeometry alignment = Alignment.center, ImageRepeat repeat = ImageRepeat.noRepeat, Rect? centerSlice, bool matchTextDirection = false, bool gaplessPlayback = false, bool isAntiAlias = false, bool scrollAwareEnable = false, FilterQuality filterQuality = FilterQuality.low})

Creates a widget that displays an image.

const

Properties

alignment → AlignmentGeometry

How to align the image within its bounds.

final

centerSlice → Rect?

The center slice for a nine-patch image.

final

color → Color?

If non-null, this color is blended with each image pixel using colorBlendMode.

final

colorBlendMode → BlendMode?

Used to combine color with this image.

final

errorBuilder → ImageErrorWidgetBuilder?

A builder function that is called if an error occurs during image loading.

final

excludeFromSemantics → bool

Whether to exclude this image from semantics.

final

filterQuality → FilterQuality

The rendering quality of the image.

final

fit → BoxFit?

How to inscribe the image into the space allocated during layout.

final

frameBuilder → ImageFrameBuilder?

A builder function responsible for creating the widget that represents this image.

final

gaplessPlayback → bool

Whether to continue showing the old image (true), or briefly show nothing (false), when the image provider changes. The default value is false.

final

hashCode → int

The hash code for this object.

no setter, inherited

height → double?

If non-null, require the image to have this height.

final

image → ImageProvider<Object>

The image to display.

final

imageBuilder → CustomImageBuilder?

final

isAntiAlias → bool

Whether to paint the image with anti-aliasing.

final

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

loadingBuilder → ImageLoadingBuilder?

A builder that specifies the widget to display to the user while an image is still loading.

final

matchTextDirection → bool

Whether to paint the image in the direction of the TextDirection.

final

opacity → Animation<double>?

If non-null, the value from the Animation is multiplied with the opacity of each image pixel before painting onto the canvas.

final

repeat → ImageRepeat

How to paint any portions of the layout bounds not covered by the image.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

scrollAwareEnable → bool

Whether to avoid loading images when rapidly scrolling.

final

semanticLabel → String?

A Semantic description of the image.

final

width → double?

If non-null, require the image to have this width.

final

Methods

createElement() → StatefulElement

Creates a StatefulElement to manage this widget's location in the tree.

inherited

createState() → State<ImageExt>

Creates the mutable state for this widget at a given location in the tree.

override

debugDescribeChildren() → List<DiagnosticsNode>

Returns a list of DiagnosticsNode objects describing this node's children.

inherited

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode

Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.

inherited

toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String

A string representation of this object.

inherited

toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String

Returns a string representation of this node and its descendants.

inherited

toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String

Returns a one-line detailed description of the object.

inherited

toStringShort() → String

A short, textual description of this widget.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited