如何验证资产（在 flutter 插件中）在 iOS 中可用

Question

I have an app written in flutter and with native bindings on android (java) and iOS (objective-c).

The app is build as a flutter plugin for the native layer bindings and this is then wrapped into a flutter app for UI etc.

The flutter plugin requires a binary dynamic library, but I struggle to get it to load on iOS. I am however unsure if this is because the library asset (eg mylib.dylib) is included in the app or if the code for finding it is broken.

Is there a way to verify that the library is actually included in the app when building it for iOS? Maybe if there is a way to get it to list all assets with location so I can look through the list and verify that the location matches what I expect it to be.

I have added a line to my pubspec.yaml on the flutter plugin like

assets: - ios/Assets/mylib.dylib

The lib file is located in pluginroot/ios/Assets/ so I would expect that this is the right location.

In the Objective-C code I have used

NSString* key = [registrar lookupKeyForAsset:@"ios/Assets/mylib.dylib"];

NSString* path = [[NSBundle mainBundle] pathForResource:key ofType:nil];

but path is empty at this point.

The flutter plugin is not able to run on its own (i haven't extended the "example" app to exercise this part of the code), so only way for me to use this is by loading the flutter plugin into my UI flutter app and then see how it goes.

Since the flutter plugin should already contain the asset, I would not expect the UI app to also have to add the asset to the pubspec - is this correct?

Answer 1

You must specify which package the image comes from.

NSString *backImgKey = [registrar lookupKeyForAsset:@"images/ic_back.png" fromPackage:@"you_package_name"];
NSString *backImgPath = [[NSBundle mainBundle] pathForResource:backImgKey ofType:nil];