StreamNetworkImage class

A network image component with automatic caching, error handling, and tap-to-reload support.

StreamNetworkImage loads and displays an image from a URL with built-in caching. If the image fails to load, it shows an error widget that can be tapped to retry the request.

{@tool snippet}

Basic usage:

StreamNetworkImage('https://example.com/photo.jpg')

{@end-tool}

{@tool snippet}

With custom placeholder and error handling:

StreamNetworkImage(
  'https://example.com/photo.jpg',
  width: 200,
  height: 200,
  fit: BoxFit.cover,
  placeholderBuilder: (context) => const CircularProgressIndicator(),
  errorBuilder: (context, error, retry) => TextButton(
    onPressed: retry, // nullable -- null when retry is not available
    child: const Text('Retry'),
  ),
)

{@end-tool}

{@tool snippet}

Auto-retry on external events (e.g. network reconnection):

StreamNetworkImage(
  'https://example.com/photo.jpg',
  retryListenable: myConnectivityNotifier,
)

{@end-tool}

See also:

• StreamNetworkImagePlaceholderBuilder, the placeholder builder typedef.
• StreamNetworkImageErrorBuilder, the error builder typedef.
• StreamImageLoadingPlaceholder, the default loading placeholder.
• StreamImageErrorPlaceholder, the default error surface with retry.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• StreamNetworkImage

Constructors

StreamNetworkImage(String url, {Key? key, Map<String, String>? httpHeaders, double? width, double? height, int? cacheWidth, int? cacheHeight, BoxFit? fit, Alignment alignment = Alignment.center, Color? color, Animation<double>? opacity, BlendMode? colorBlendMode, FilterQuality filterQuality = FilterQuality.low, String? cacheKey, String? semanticLabel, bool excludeFromSemantics = false, StreamNetworkImagePlaceholderBuilder? placeholderBuilder, StreamNetworkImageErrorBuilder? errorBuilder, Listenable? retryListenable})

Creates a network image with automatic caching and error handling.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

props → StreamNetworkImageProps

The properties that configure this network image.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

override

createElement() → StatelessElement

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

inherited

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.

inherited

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, int wrapWidth = 65}) → 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

Static Methods

evictFromCache(String url, {String? cacheKey}) → Future<bool>

Evicts a single image from both disk and in-memory caches.