javafx - 无法运行 JavaFX - Kotlin 应用程序

Question

我无法运行我的 javafx - kotlin 应用程序。

我的初学者类(class)

class Starter : Application() {

  override fun start(primaryStage: Stage?) {
      val root : Parent = FXMLLoader.load(javaClass.getResource("view/main.fxml"))
      primaryStage?.title = "Title"
      primaryStage?.scene = Scene(root)
      primaryStage?.show()
  }

  fun main(args: Array<String>) {
      launch(args)
  }
}

我无法将参数“args”传递给“launch”方法，因为编译器说:

Error:(19, 9) Kotlin: None of the following functions can be called with the arguments supplied: public open fun launch(p0: Class!, vararg p1: String!): Unit defined in javafx.application.Application public open fun launch(vararg p0: String!): Unit defined in javafx.application.Application

如果我尝试在没有参数的情况下调用“launch”方法，我会遇到以下异常

Exception in thread "main" java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767) Caused by: java.lang.NullPointerException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389) at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328) ... 5 more

Answer 1

你需要使用传播运算符

fun main(args: Array<String>) {
    Application.launch(Starter::class.java, *args)
}