如何在 flutter Package/Plugin 开发中添加资产？

Question

I am developing a flutter package containing some assets files. I mentioned required assets in pubsepc.yaml as usual like this

  assets:
    - assets/abc.xyz

and uploaded the package to https://pub.dartlang.org/ .

After that I created a flutter Application and imported my developed package in pubspec.yaml like...

dependencies:
  flutter:
    sdk: flutter
  my_developed_package: ^0.0.1

Now everything is working fine except my assets are absent. I put some assets in my Application without mentioning in pubsepc.yaml and its working. I am unable to understand, how do I add these assets to my package so that they load automatically?

Answer 1

Quote from

If the desired asset is specified in the pubspec.yaml file of the package, it is bundled automatically with the application. In particular, assets used by the package itself must be specified in its pubspec.yaml.

In Flutter you can use assets from packages, it should not be a problem. Only thing is, you need to specify your package and import it. Eg If it's an image, you can use AssetImage class and it's package attribute.

AssetImage('assets/abc.xyz', package: 'my_developed_package');

For more information about how you can call texts and other stuff, please check here .

Answer 2

Sorry for the late answer but the following approach helped me for including assets (not only images but any type of file) in plugin development.

I put my assets under the lib folder like, my_plugin/lib/assets and in pubspec.yaml like this.

  assets:
    - packages/my_plugin/assets/asset_name
       
  # Be careful about indentation

It has been added with the plugin and then I accessed them with path like this packages/my_plugin/assets/asset_name , eg

File myAsset = File("packages/my_plugin/assets/asset_name");

By this approach, I was able to get any asset from Plugin not only Images.

For a complete Example, you can check my plugin here .

Answer 3

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:

.../pubspec.yaml
.../icons/heart.png
.../icons/1.5x/heart.png
.../icons/2.0x/heart.png
...etc.

To load the image, use:

AssetImage('icons/heart.png', package: 'my_icons')

Assets used by the package itself should also be fetched using the package argument as above.

Answer 4

Pubspec yaml is indentation sensitive

there is a difference between

 assets:
  - packages/my_plugin/assets/asset_name

VS

 assets:
   - packages/my_plugin/assets/asset_name

If you closely notice at above two then you will find that pubspec.yaml is very sensitive

always write

assets:
  -asset/yourasset/example1

there must be two spaces from the beginning of line.

After adding asset link to pubspec you have to run packages get It will show exits with 0 error if you place your assets properly otherwise it will show you reason behind the error.

Generally, Beginners face these type of problems. With time you will crack the way to solve this error

Answer 5

Adding Assets to a Flutter Package can get Difficult!
Just follow these steps and you're good to go...

Step 1: Make an assets folder in the root directory of the Package

Step 2: Add it to your pubspec.yaml file

flutter:
  assets:
    - assets/asset_name

# Mind the indentation

Step 3: Using the asset , for an image file

AssetImage('assets/asset_name.png', package: 'your_package_name')

Run Pub.dev and do a Cold Start for the Flutter Application using the Package and

Voila You're Done.