如何使用TornadoFX树视图显示数据

Question

我正在学习如何使用kotlin，并已开始使用tornadoFX。我正在尝试阅读指南，但是我无法弄清楚“具有不同类型的TreeView”的含义。似乎我应该使用星形投影，当您在通话中使用*时，我就知道。

但是，一旦我这样做，树视图就会说“不允许在函数和属性的类型参数上进行投影”

这是我的代码：

MainView类：View（“”）{

override val root = treeview<*> {
        root = TreeItem(Person("Departments", ""))

        cellFormat {
            text = when (it) {
                is String -> it
                is Department -> it.name
                is Person -> it.name
                else -> throw IllegalArgumentException("Invalid Data Type")
            }
        }

        populate { parent ->
            val value = parent.value
            if (parent == root) departments
            else if (value is Department) persons.filter { it.department == value.name }
            else null
        } }

}

老实说，我很沮丧，我不知道我要做什么。

另外，如果任何人都可以为我提供一些学习Kotlin和tornadoFX的有用链接，将不胜感激:)

Answer 1

看来该指南实际上是不正确的。我使用它工作treeview<Any>：

data class Department(val name: String)
data class Person(val name: String, val department: String)

val persons = listOf(
        Person("Mary Hanes", "Marketing"),
        Person("Steve Folley", "Customer Service"),
        Person("John Ramsy", "IT Help Desk"),
        Person("Erlick Foyes", "Customer Service"),
        Person("Erin James", "Marketing"),
        Person("Jacob Mays", "IT Help Desk"),
        Person("Larry Cable", "Customer Service")
)

val departments = persons.groupBy { Department(it.department) }

override val root = treeview<Any> {
    root = TreeItem("Departments")
    cellFormat {
        text = when (it) {
            is String -> it
            is Department -> it.name
            is Person -> it.name
            else -> kotlin.error("Invalid value type")
        }
    }
    populate { parent ->
        val value = parent.value
        when {
            parent == root -> departments.keys
            value is Department -> departments[value]
            else -> null
        }
    }
}