Android Architecture Components - ViewModel Observable & Proguard

Question

我很难将ViewModel组件与Proguard一起使用。我已经不得不添加以下内容以防止由于nosuchmethodexception而导致的崩溃：init((

- keep class com .... slideShowViewModel {*;}

但是，我在活动中的观察者没有收到任何数据。在启用Proguard之前，这很好，所以我知道Proguard是原因，我只是不知道为什么(在这里新手Proguardian(。我需要添加什么规则才能使观察值正常工作？

我在ViewModel(Kotlin(

中有以下内容

val currentItem = MediatorLiveData<MediaItem>()

....以后...

        Timber.d("Setting next image: " + position + " out of " + mediaItemList.size)
        currentItem.value = mediaItemList[position]

和活动(Java(

    viewModel.getCurrentItem().observe(this, new Observer<MediaItem>() {
        @Override
        public void onChanged(@Nullable final MediaItem mediaItem) {
            Timber.d("Activity received new item");
        }
    });

在我收到的日志中：D/slideshowViewModel：设置下一个图像：18

中的0

，但没有任何东西在可观察到的可观察到。

Answer 1

在：https://issuetracker.google.com/issues/62113696

不应尽快修复(还不在alpha3中(

## Android architecture components: Lifecycle
# LifecycleObserver's empty constructor is considered to be unused by proguard
-keepclassmembers class * implements android.arch.lifecycle.LifecycleObserver {
    <init>(...);
}
# ViewModel's empty constructor is considered to be unused by proguard
-keepclassmembers class * extends android.arch.lifecycle.ViewModel {
    <init>(...);
}
# keep Lifecycle State and Event enums values
-keepclassmembers class android.arch.lifecycle.Lifecycle$State { *; }
-keepclassmembers class android.arch.lifecycle.Lifecycle$Event { *; }
# keep methods annotated with @OnLifecycleEvent even if they seem to be unused
# (Mostly for LiveData.LifecycleBoundObserver.onStateChange(), but who knows)
-keepclassmembers class * {
    @android.arch.lifecycle.OnLifecycleEvent *;
}