Firebase的数据类空构造函数

Question

data class MainPosts(val context: Context, val posts: Posts, val livePost: LivePosts?)
{
    constructor() : this(null!!, null!!, null!!) 
}

嘿,我一直在试图弄清楚如何在Firebase的数据类上创建一个空的构造函数.

我尝试了上面的代码,但它没有正常工作.

Answer 1

要获取默认构造函数,您应该初始化值:

data class MainPosts(
    val context: Context = someDefaultValue1, 
    val posts: Posts = someDefaultValue2, 
    val livePost: LivePosts? = null) 

如果从构造函数代码看起来它们都是可空的:

data class MainPosts(
    val context: Context? = null, 
    val posts: Posts? = null, 
    val livePost: LivePosts? = null) 

这给你一个默认的构造函数.