onaction=“#ClickedClickMe”在JavaFX FXML中无法工作

Question

早上好！我刚刚开始学习Java FX和Java FX FXML。我使用Scene Builder构建GUI，使用Netbeans编写剩余的Java FX程序。

我面临的问题是在FXML文件中。Netbeans编辑器在onAction事件的.fxml文件中的以下代码中显示错误。

如果我使用Netbeans创建一个示例项目，它使用AnchorPane，似乎一切都很好。但是，如果我删除AnchorPane并添加任何其他窗格和按钮，onAction事件就不起作用了！

我是这门语言的初学者，因此任何帮助/指导都非常感谢！

注意：我花了将近半天的时间在StackOverflow上浏览所有可用的解决方案。

<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.event.ActionEvent?>

<GridPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111">
  <columnConstraints>
    <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
    <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
  </columnConstraints>
  <rowConstraints>
    <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
    <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
    <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
  </rowConstraints>
   <children>
      <Button mnemonicParsing="false" onAction="#ClickedClickMe" text="Click Me!" GridPane.columnIndex="1" GridPane.rowIndex="1" />
      <Label fx:id="label" GridPane.columnIndex="1" GridPane.rowIndex="2" />
   </children>
</GridPane>

package sample1;

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

public class Sample1 extends Application {

    @Override
    public void start(Stage stage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));

        Scene scene = new Scene(root);

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

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

}

FXMLDocumentController.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package sample1;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;

public class FXMLDocumentController implements Initializable {

    @FXML
    private Label label;

    @FXML
    private void ClickedClickMe(ActionEvent event) {
        System.out.println("You clicked me!");
        label.setText("Clicked Try me!!");
    }

    @Override
    public void initialize(URL url, ResourceBundle rb) {
        // TODO
    }    

}

Answer 1

在fxml文件中设置控制器

<GridPane fx:controller="sample1.FXMLDocumentController" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111">