将 SceneBuilder 连接到 fxmlloader

Question

我在 IntelliJ 中制作了这个简短的绘图应用程序，并且我第一次尝试使用 SceneBuilder。我在场景生成器中制作的 "sample.fxml" 不会加载到我的 Main-class 中，所以我自己直接在 Main-class 中制作了 Canvas 等。我对 FXML loader/file 做错了什么？

package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Group;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        try {
//            FXMLLoader load = FXMLLoader.load(getClass().getResource("sample.fxml"));
//            load.load();
            Group root = new Group();
            Controller controller = new Controller();
            primaryStage.setTitle("Paint app");
            primaryStage.setScene(new Scene(root,800,500));
            primaryStage.show();
            root.getChildren().add(controller.canvas);

            /*METODER I PROGRAMMET */
            controller.drawCanvas();

        }catch (Exception e){
            System.out.println(e);
            System.exit(0);
        }
    }


    public static void main(String[] args) {
        launch(args);
    }
}

package sample;

import javafx.fxml.FXML;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.paint.Color;

public class Controller {
    Canvas canvas = new Canvas(800,500);


    @FXML
    public void drawCanvas(){

        GraphicsContext gc = canvas.getGraphicsContext2D();
        gc.setLineWidth(3);
        gc.setStroke(Color.BLACK);
        System.out.println("drawCanvas");

        try {
            canvas.setOnMousePressed(event -> {
                System.out.println("Mouse click");
                gc.beginPath();
                gc.lineTo(event.getSceneX(), event.getSceneY());
                gc.stroke();
            });

            canvas.setOnMouseDragged(event -> {
                System.out.println("Mouse dragged");
                gc.lineTo(event.getSceneX(), event.getSceneY());
                gc.stroke();
            });
        }catch (Exception e){
            System.out.println(e);
            System.exit(0);
        }

    }
}

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.canvas.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>


<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
   <center>
      <Canvas id="canvas" fx:id="canvas" height="359.0" onMouseClicked="#drawCanvas" onMouseDragged="#drawCanvas" width="394.0" BorderPane.alignment="CENTER" />
   </center>
</BorderPane>

关于 scenebuilder 的文档不多。谢谢！

Answer 1

我使用了您的 fxml 和控制器，并将它们添加到我在 Netbeans 中创建的项目中，并且成功了。

This is your problem:

变化：

Canvas canvas = new Canvas(800,500);

至：

@FXML  Canvas canvas;

在您的控制器中

Sample.java

package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Sample extends Application
{    
    @Override
    public void start(Stage stage) throws Exception
    {
        Parent root = FXMLLoader.load(getClass().getResource("Sample.fxml"));//You may need so make the s lowercase.

        Scene scene = new Scene(root);

        stage.setScene(scene);
        stage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        launch(args);
    }

}

Controller.java

package sample;

import javafx.fxml.FXML;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.paint.Color;

public class Controller {

    @FXML  Canvas canvas;

    @FXML
    public void drawCanvas(){

        GraphicsContext gc = canvas.getGraphicsContext2D();
        gc.setLineWidth(3);
        gc.setStroke(Color.BLACK);
        System.out.println("drawCanvas");

        try {
            canvas.setOnMousePressed(event -> {
                System.out.println("Mouse click");
                gc.beginPath();
                gc.lineTo(event.getSceneX(), event.getSceneY());
                gc.stroke();
            });

            canvas.setOnMouseDragged(event -> {
                System.out.println("Mouse dragged");
                gc.lineTo(event.getSceneX(), event.getSceneY());
                gc.stroke();
            });
        }catch (Exception e){
            System.out.println(e);
            System.exit(0);
        }

    }
}

Sample.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.canvas.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>


<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
   <center>
      <Canvas id="canvas" fx:id="canvas" height="359.0" onMouseClicked="#drawCanvas" onMouseDragged="#drawCanvas" width="394.0" BorderPane.alignment="CENTER" />
   </center>
</BorderPane>

Answer 2

不太确定为什么，但我尝试将其更改几次，它确实有效：谢谢@Sedrick Jefferson

package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Group;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        try {
            Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
            primaryStage.setTitle("Paint app");
            primaryStage.setScene(new Scene(root));
            primaryStage.show();

        }catch (Exception e){
            System.out.println(e);
            System.exit(0);
        }
    }


    public static void main(String[] args) {
        launch(args);
    }
}

将 SceneBuilder 连接到 fxmlloader

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