text stringlengths 1 474 |
|---|
Flutter bundles the variants for you. |
Each entry should correspond to a real file, with the exception of |
the main asset entry. If the main asset entry doesn’t correspond |
to a real file, then the asset with the lowest resolution |
is used as the fallback for devices with device pixel |
ratios below that resolution. The entry should still |
be included in the pubspec.yaml manifest, however.Anything using the default asset bundle inherits resolution |
awareness when loading images. (If you work with some of the lower |
level classes, like ImageStream or ImageCache, |
you’ll also notice parameters related to scale.)<topic_end> |
<topic_start> |
Asset images in package dependencies |
To load an image from a package dependency, |
the package argument must be provided to AssetImage.For instance, suppose your application depends on a package |
called my_icons, which has the following directory structure:To load the image, use: |
<code_start>return const AssetImage('icons/heart.png', package: 'my_icons');<code_end> |
Assets used by the package itself should also be fetched |
using the package argument as above.<topic_end> |
<topic_start>Bundling of package assets |
If the desired asset is specified in the pubspec.yaml |
file of the package, it’s bundled automatically with the |
application. In particular, assets used by the package |
itself must be specified in its pubspec.yaml.A package can also choose to have assets in its lib/ |
folder that are not specified in its pubspec.yaml file. |
In this case, for those images to be bundled, |
the application has to specify which ones to include in its |
pubspec.yaml. For instance, a package named fancy_backgrounds |
could have the following files:To include, say, the first image, the pubspec.yaml of the |
application should specify it in the assets section:The lib/ is implied, |
so it should not be included in the asset path.If you are developing a package, to load an asset within the package, specify it in the pubspec.yaml of the package:To load the image within your package, use:<topic_end> |
<topic_start> |
Sharing assets with the underlying platform |
Flutter assets are readily available to platform code |
using the AssetManager on Android and NSBundle on iOS.<topic_end> |
<topic_start> |
Loading Flutter assets in Android |
On Android the assets are available through the |
AssetManager API. The lookup key used in, |
for instance openFd, is obtained from |
lookupKeyForAsset on PluginRegistry.Registrar or |
getLookupKeyForAsset on FlutterView. |
PluginRegistry.Registrar is available when developing a plugin |
while FlutterView would be the choice when developing an |
app including a platform view.As an example, suppose you have specified the following |
in your pubspec.yamlThis reflects the following structure in your Flutter app.To access icons/heart.png from your Java plugin code, |
do the following:<topic_end> |
<topic_start> |
Loading Flutter assets in iOS |
On iOS the assets are available through the mainBundle. |
The lookup key used in, for instance pathForResource:ofType:, |
is obtained from lookupKeyForAsset or lookupKeyForAsset:fromPackage: |
on FlutterPluginRegistrar, or lookupKeyForAsset: or |
lookupKeyForAsset:fromPackage: on FlutterViewController. |
FlutterPluginRegistrar is available when developing |
a plugin while FlutterViewController would be the choice |
when developing an app including a platform view.As an example, suppose you have the Flutter setting from above.To access icons/heart.png from your Objective-C plugin code you |
would do the following:To access icons/heart.png from your Swift app you |
would do the following:For a more complete example, see the implementation of the |
Flutter video_player plugin on pub.dev.The ios_platform_images plugin on pub.dev wraps |
up this logic in a convenient category. You fetch |
an image as follows:Objective-C:Swift:<topic_end> |
<topic_start> |
Loading iOS images in Flutter |
When implementing Flutter by |
adding it to an existing iOS app, |
you might have images hosted in iOS that you |
want to use in Flutter. To accomplish |
that, use the ios_platform_images plugin |
available on pub.dev.<topic_end> |
<topic_start> |
Platform assets |
There are other occasions to work with assets in the |
platform projects directly. Below are two common cases |
where assets are used before the Flutter framework is |
loaded and running.<topic_end> |
<topic_start> |
Updating the app icon |
Updating a Flutter application’s launch icon works |
the same way as updating launch icons in native |
Android or iOS applications.<topic_end> |
<topic_start>Android |
In your Flutter project’s root directory, navigate to |
.../android/app/src/main/res. The various bitmap resource |
folders such as mipmap-hdpi already contain placeholder |
images named ic_launcher.png. Replace them with your |
desired assets respecting the recommended icon size per |
screen density as indicated by the Android Developer Guide.info Note |
If you rename the .png files, you must also update the |
corresponding name in your AndroidManifest.xml’s |
<application> tag’s android:icon attribute.<topic_end> |
<topic_start>iOS |
In your Flutter project’s root directory, |
navigate to .../ios/Runner. The |
Assets.xcassets/AppIcon.appiconset directory already contains |
placeholder images. Replace them with the appropriately |
sized images as indicated by their filename as dictated by the |
Apple Human Interface Guidelines. |
Keep the original file names.<topic_end> |
<topic_start> |
Updating the launch screen |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.