Question

我有一个场景。我在Kotlin中创建了一个数据类，如下所示：

data class AgentDetails(
        val mobileNo: String,
        val Name: String,
        val Email: String,
        val Password: String,
        val Occupation: String,
        val pincode: String,
        val usertype: String,
        val profilepic: String,
        val AccountStatus: String
)

我想将此数据类的不同类型的对象发送到Web服务：

第一个对象示例：

val agentDetails = AgentDetails(mobileNo = mobileNumberText.text.toString(),
                        Name = userNameText.text.toString(),
                        Email = emailIdText.text.toString(),
                        Password = HashUtils.sha1(passwordText.text.toString()),
                        Occupation = item,
                        pincode = pinCodeText.text.toString(),
                        usertype = "Agent",
                        profilepic = "null", AccountStatus = "pending")

在第二个对象中我只想发送手机号码。我不想包括任何其他领域。像这样：

val agentDetails = AgentDetails(mobileNo = mobileNumberText.text.toString())

在第3个对象中，我只想发送电子邮件ID。而不是创建多个数据类。我可以为多个实现使用相同的数据类吗？

Answer 1

最简单的方法是使字段可以为空并提供默认值：

data class AgentDetails(
    val mobileNo: String? = null,
    val Name: String? = null,
    val Email: String? = null,
    val Password: String? = null,
    val Occupation: String? = null,
    val pincode: String? = null,
    val usertype: String? = null,
    val profilepic: String? = null,
    val AccountStatus: String? = null
)

Answer 2

就个人而言，我定义了三个对象，因为它们代表三个不同的概念（或概念的投影）。但是如果你使你的属性可以为空并提供一个默认值null，你可以随意创建它们......

data class AgentDetails(
    val mobileNo: String? = null,
    val name: String? = null,
    val email: String? = null,
    val password: String? = null,
    val occupation: String? = null,
    val pincode: String? = null,
    val usertype: String? = null,
    val profilepic: String? = null,
    val accountStatus: String? = null
)

注意：我已经将一些属性名称更改为camelCase，这是正确的约定。这一切都很好：

AgentDetails(mobileNo = mobileNumberText.text.toString())
AgentDetails(email = "foo@example.com")
AgentDetails(name = "Foo", password = "Bar")

未提供的所有其他字段都将为null，并且类型将为可空，因此您必须防范它。否则，我为此定义了三个数据类。

另一种解决方案是考虑密封的类结构：

sealed class AgentDetails
data class AgentByName(val name: String) : AgentDetails()
data class AgentByEmail(val email: String): AgentDetails()
// etc..

然后在when表达式中使用它：

fun doSomethingWithAgents(agentDetails: AgentDetails) {
    when (agentDetails) {
        is AgentByName -> // Do something
        is AgentByEmail -> // Do Something
    }
}

自定义单个数据类，而无需在Kotlin中创建多个数据类

2 个答案: