Kotlin 1.0.2房间数据库

Question

I'm using koin 1.0.2 to manage dependencies injection but it's not working with room database, it's returning can't create definition for single... Here is my code:

@Database(entities = [UserEntity::class], version = 1, exportSchema = false)
abstract class UserDatabase : RoomDatabase() {

    abstract fun userDao(): UserDao

    companion object {

        private var INSTANCE: UserDatabase? = null

        fun getInstance(context: Context): UserDatabase {
            if (INSTANCE == null) {

                INSTANCE = Room.databaseBuilder(
                        context,
                        UserDatabase::class.java,
                        "user_database")
                        .allowMainThreadQueries()
                        .build()
            }

            return INSTANCE!!
        }
    }
}


val DatabaseModule = module {

   single { UserDatabase.getInstance( get())}

}

class UserApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        startKoin(getModules())
    }
    private fun getModules() = listOf(DatabaseModule, RepositoryModule, ViewModule)
}

Answer 1

I have tried your code in a test project with sample entities and it worked. Since you haven't posted the actual error description, please do/ensure the following steps and try again.

Add the following dependencies to build.gradle

implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version"

If you are using RxJava for room, then add the following line as well

implementation "androidx.room:room-rxjava2:$room_version"

Apply the kotlin-kapt plugin

apply plugin: 'kotlin-kapt'

clean and build.

If you are still experiencing the problem, consider editing the question with logcat stack trace.

Answer 2

Have you declared a definition for a Context object in other modules? Because your database method needs this one and you are calling get() to resolve it. If not, just change

single { UserDatabase.getInstance(get()) }

to

single { UserDatabase.getInstance(androidContext()) }