实施 Room 时出错

Question

错误：

Entities and Pojos must have a usable public constructor. You can have an empty constructor or a constructor whose parameters match the fields (by name and type).  

我的实体是

@Entity
data class Category(var category: String) {

@field: PrimaryKey(autoGenerate = true)
var categoryId: Int = 0


}

Answer 1

根据错误信息，您需要为该类添加构造函数。

@Entity data class Category(var category: String) {

@field: PrimaryKey(autoGenerate = true) var categoryId: Int = 0

constructor() : this(0) 

}