如何解决此 Android SQLite Room DAO 错误消息？

Question

我不知道下面的问题是怎么回事？

代码：

CategoryDAO.kt

@Dao
interface CategoryDAO {
    @Query("select * from CategoryDesign")
    suspend fun getCategory(): MutableLiveData<List<CategoryDesign>>


}

CategoryDesign.kt

@Entity
data class CategoryDesign (
    @PrimaryKey
    var categoryDesignID:String,
    var designImage:String,
    var designTitle:String){
    constructor() : this("","","")

    override fun toString(): String {
        return designTitle
    }
}

按运行应用程序按钮将显示如下错误：

error: Not sure how to convert a Cursor to this method's return type (androidx.lifecycle.MutableLiveData<java.util.List<com.squall.searchdesigner.model.CategoryDesign>>).
    public abstract java.lang.Object getCategory(@org.jetbrains.annotations.NotNull()


w: [kapt] Incremental annotation processing requested, but support is disabled because the following processors are not incremental: androidx.room.RoomProcessor (DYNAMIC), android.databinding.annotationprocessor.ProcessDataBinding (DYNAMIC).

依赖项：

dependencies {
    def room_version = "2.2.3"
kapt "androidx.room:room-compiler:$room_version"
implementation "androidx.room:room-ktx:$room_version"
}

Answer 1

好像只能使用LiveData return类型。也许 Room 不允许您使用 MutableLiveData？

Answer 2

谢谢大家。我使用下面的代码重建项目并使缓存无效似乎解决了这个问题。

@Dao
interface CategoryDAO {
    @Query("select * from CategoryDesign")
    fun getCategory(): LiveData<MutableList<CategoryDesign>>


}

如何解决此 Android SQLite Room DAO 错误消息？

How to solve this Android SQLite Room DAO error message?

android

dao

android-sqlite

android-room