无法在另一个 class 程序中使用 JavaFX 程序的 static 方法

Question

I have created a method to show a dialogue box with suitable information when called. I have created another test class to call and test the method which I have previously mentioned. When I call the method using this test class it shows some errors which I am not able to solve. Thanks in advance...

    package my_classes;

    import javafx.stage.*;
    import javafx.geometry.Pos;
    import javafx.scene.*;
    import javafx.scene.control.*;
    import javafx.scene.layout.*;

    public class MessageBox
    {
        public static void show(String label, String button, String title, int xaxis, int yaxis)
        {
            Stage window=new Stage();
            Scene sc;
            Button btn=new Button(button);
            btn.setOnAction(e -> window.close());
            Label lbl=new Label(label);
            window.setTitle(title);
            VBox vb=new VBox(50);
            vb.getChildren().addAll(lbl,btn);
            vb.setAlignment(Pos.CENTER);
            sc=new Scene(vb,xaxis,yaxis);
            window.setMaxHeight(yaxis+100);
            window.setMaxWidth(xaxis+100);
            window.setMinHeight(yaxis-100);
            window.setMinWidth(xaxis-100);
            window.initModality(Modality.APPLICATION_MODAL);
            window.setScene(sc);
            window.showAndWait();
        }
    }

    package my_classes;

    public class test
    {
        public static void main(String args[])
        {
            MessageBox.show("This is a piece of text", "OK", "Test", 500, 300);
        }
    }

"image of the error message"

Answer 1

You need to use the normal JavaFX application startup procedure. That means inheriting from the Application class and using the launch() method in order to properly initialize the JavaFX runtime.

For example:

public class MyApplication extends Application {
    /**
     * Initialize the application
     *
     * @param args The application arguments
     */
    public static void main(final String[] args) {
        launch(args);
    }

    @Override
    public void start(final Stage primaryStage) {
       // Code here
    }
}

Please take your time to read the JavaFX documentation:
https://openjfx.io/javadoc/15/