类型不匹配：推断类型为 AutoMigration，但预期为 KClass<*>

Question

我试图实现一个简单的自动迁移，它只是将一个可为空的字符串字段添加到我的 table，但由于某种原因，我在 autoMigrations = [AutoMigration(from = 1, to = 2)] 行中收到以下错误：

Type mismatch: inferred type is AutoMigration but KClass<*> was expected

我说这是一个奇怪的错误，因为即使 documentation has it this way.

完整代码如下：

@Database(
    version = 2,
    entities = [Note::class],
    autoMigrations = [AutoMigration(from = 1, to = 2)]
)
@TypeConverters(Converters::class)
abstract class NotesDB : RoomDatabase() {
    abstract fun noteDao(): NoteDao

    companion object {
        @Volatile
        private var INSTANCE: NotesDB? = null

        fun getDB(context: Context): NotesDB {
            return INSTANCE ?: synchronized(this) {
                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    NotesDB::class.java,
                    "notesDB"
                ).build()
                INSTANCE = instance
                instance
            }
        }
    }
}

Answer 1

将 build.gradle 中的房间版本更改为最新版本（目前为 2.4.0-alpha04）。然后如果你会得到一个关于 room.schemaLocation 的错误，看看这个答案

类型不匹配：推断类型为 AutoMigration，但预期为 KClass<*>

Type mismatch: inferred type is AutoMigration but KClass<*> was expected

android

kotlin

android-room