房间错误：参数的类型必须是使用 @Entity 注释的类或其集合/数组。即使添加了 androidx.room:room-ktx

Question

根据我对 “suspend” 关键字的理解。 但是我已经添加了 implementation("androidx.room:room-ktx:$roomVersion") 依赖

Gradle 文件是：

 plugins {
        id 'com.android.application'
        id 'kotlin-android'
        id 'kotlin-kapt'
    }
    
    android {
        compileSdk 31

    defaultConfig {
        applicationId "com.kaushik.roomdemo"
        minSdk 21
        targetSdk 31
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    buildFeatures{
        viewBinding true
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
}

dependencies {

    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.0'
    implementation 'com.google.android.material:material:1.4.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.2'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

    def lifecycle_version = "2.4.0"
    def roomVersion = "2.3.0"

    // ViewModel
    implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version")

    // LiveData
    implementation("androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version")

    // Annotation processor
    implementation "androidx.lifecycle:lifecycle-common-java8:$lifecycle_version"

    // Room
    implementation("androidx.room:room-runtime:$roomVersion")
    kapt("androidx.room:room-compiler:$roomVersion")

    // Kotlin Extensions and Coroutines support for Room
    implementation("androidx.room:room-ktx:$roomVersion")

    // Coroutines
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-RC'
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0-RC'

    // Activity KTX for viewModels()
    implementation "androidx.activity:activity-ktx:1.4.0"
}

实体是：

@Entity(tableName = "subscriber_table")
data class Subscriber(
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name="subscriber_id")
    val id:Int,
    @ColumnInfo(name="subscriber_name")
    val name:String,
    @ColumnInfo(name="subscriber_email")
    val email:String
)

道是：

@Dao
interface SubscriberDao {
    @Query("SELECT * from subscriber_table")
    fun getAllSubscriber(): LiveData<List<Subscriber>>

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    suspend fun addSubscriber(subscriber: Subscriber):Long

    @Delete
    suspend fun deleteSubscriber(subscriber: Subscriber)
}

数据库是：

@Database(entities = [Subscriber::class], version = 1)
abstract class SubscriberDataBase:RoomDatabase() {

    abstract fun subscriberDao(): SubscriberDao

    companion object{
        @Volatile
        private var INSTANCE: SubscriberDataBase? = null
        fun getInstance(context: Context):SubscriberDataBase{
            synchronized(this){
                var instance:SubscriberDataBase? = INSTANCE
                if(instance == null) {
                    instance = Room.databaseBuilder(
                        context.applicationContext,
                        SubscriberDataBase::class.java,
                        "Subscriber_DataBase"
                    ).build()
                }
                return instance
            }
        }
    }
}

现在每次我尝试构建代码时都会引发以下错误： D:\CODE IT\Android Developmeent\RoomDemo\app\build\tmp\kapt3\stubs\debug\com\kaushik\roomdemo\db\SubscriberDao.java:17: error: Type of the parameter must be a class用 @Entity 或它的集合/数组注释。 kotlin.coroutines.Continuation super java.lang.Long> 续）；

我已经在依赖文件中添加了实现("androidx.room:room-ktx:$roomVersion")。 还是不行。任何人，请帮助！！！！！！！！！！！！！！！！！！！！！！！！！！！！！

Answer 1

您的代码看起来不错，您可能尚未在 RoomDatabase() 类中定义您的实体。

@Database(
    entities = [Subscriber::class],
    version = 1,
    exportSchema = false
)
abstract class AppDatabase : RoomDatabase() {
   //...
}

Answer 2

试试这个..也许它会帮助你

@Dao
interface SubscriberDao {
    @Query("SELECT * from subscriber_table")
    fun getAllSubscriber(): LiveData<List<Subscriber>>

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    fun addSubscriber(subscriber: Subscriber):Long

    @Delete
    fun deleteSubscriber(subscriber: Subscriber)
}