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.
When a network image is used on the Web platform, the getTargetSize
parameter of the ImageDecoderCallback is only supported when the
application is running with the CanvasKit renderer. When the application is
using the HTML renderer, the web engine delegates image decoding of network
images to the Web, which does not support custom decode sizes.
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
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
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