NetworkImage class abstract
Fetches the given URL from the network, associating it with the given scale.
The image will be cached regardless of cache headers from the server.
Typically this class resolves to an image stream that ultimately produces
dart:ui.Images. On the Web platform, the webHtmlElementStrategy
parameter can be used to make the image stream ultimately produce an
WebImageInfo
instead, which makes Image.network display the image as an
HTML element in a platform view. The feature is by default turned off
(WebHtmlElementStrategy.never). See Image.network for more explanation.
See also:
- Image.network for a shorthand of an Image widget backed by NetworkImage.
- The example at ImageProvider, which shows a custom variant of this class that applies different logic for fetching the image.
- Inheritance
-
- Object
- ImageProvider<
NetworkImage> - NetworkImage
Constructors
-
NetworkImage(String url, {double scale, Map<
String, String> ? headers, WebHtmlElementStrategy webHtmlElementStrategy}) -
Creates an object that fetches the image at the given URL.
constfactory
Properties
- hashCode → int
-
The hash code for this object.
no setterinherited
-
headers
→ Map<
String, String> ? -
The HTTP headers that will be used with HttpClient.get to fetch image from network.
no setter
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- scale → double
-
The scale to place in the ImageInfo object of the image.
no setter
- url → String
-
The URL from which the image will be fetched.
no setter
- webHtmlElementStrategy → WebHtmlElementStrategy
-
On the Web platform, specifies when the image is loaded as a
WebImageInfo
, which causes Image.network to display the image in an HTML element in a platform view.no setter
Methods
-
createStream(
ImageConfiguration configuration) → ImageStream -
Called by resolve to create the ImageStream it returns.
inherited
-
evict(
{ImageCache? cache, ImageConfiguration configuration = ImageConfiguration.empty}) → Future< bool> -
Evicts an entry from the image cache.
inherited
-
loadBuffer(
NetworkImage key, DecoderBufferCallback decode) → ImageStreamCompleter -
Converts a key into an ImageStreamCompleter, and begins fetching the
image.
override
-
loadImage(
NetworkImage key, ImageDecoderCallback decode) → ImageStreamCompleter -
Converts a key into an ImageStreamCompleter, and begins fetching the
image.
override
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
obtainCacheStatus(
{required ImageConfiguration configuration, ImageErrorListener? handleError}) → Future< ImageCacheStatus?> -
Returns the cache location for the key that this ImageProvider creates.
inherited
-
obtainKey(
ImageConfiguration configuration) → Future< NetworkImage> -
Converts an ImageProvider's settings plus an ImageConfiguration to a key
that describes the precise image to load.
inherited
-
resolve(
ImageConfiguration configuration) → ImageStream -
Resolves this image provider using the given
configuration
, returning an ImageStream.inherited -
resolveStreamForKey(
ImageConfiguration configuration, ImageStream stream, NetworkImage key, ImageErrorListener handleError) → void -
Called by resolve with the key returned by obtainKey.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited