JavaFX ContextMenu如何获取被单击的对象？ [英] JavaFX ContextMenu how do I get the clicked Object?

问题描述

我正在学习javafx.scene.control.ContextMenu，现在我面临一个问题：

I am learning javafx.scene.control.ContextMenu, and right now I am facing a problem:

如何从EventHandler中获取被单击的对象？

how do I get the clicked Object from EventHandler? both event.source() and event.target() return the MenuItem.

让我用一个例子解释一下：
我应该在函数句柄中写什么？

let me explain with an example: what should I write inside the function handle?

    TextField text = new TextField();
    Label label1 = new Label("hello");
    Label label2 = new Label("world");
    Label label3 = new Label("java");

    ContextMenu menu = new ContextMenu();
    MenuItem item = new MenuItem("copy to text field");
    menu.getItems().add(item);
    item.setOnAction(new EventHandler(){
        public void handle(Event event) {
            //I want to copy the text of the Label I clicked to TextField
            event.consume();
        }
    });

    label1.setContextMenu(menu);
    label2.setContextMenu(menu);
    label3.setContextMenu(menu);

编辑：我希望有一些简单的解决方案（一个班轮），但如果没有

I was hoping there was some simple solution (one liner), but if there isn't then there are lot's of complex way to do it.

推荐答案

您可以创建自己的ContextMenu实例并将操作父添加到以便进一步参考：

You could create your own instance of ContextMenu and add the action parent to it for further reference:

public class Main extends Application {

    TextField text = new TextField();

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

    @Override
    public void start(Stage primaryStage) {


        Label label1 = new Label("hello");
        Label label2 = new Label("world");
        Label label3 = new Label("java");

        label1.setContextMenu(new MyContextMenu(label1));
        label2.setContextMenu(new MyContextMenu(label2));
        label3.setContextMenu(new MyContextMenu(label3));

        HBox root = new HBox();

        root.getChildren().addAll(text, label1, label2, label3);

        Scene scene = new Scene(root, 300, 100);

        primaryStage.setScene(scene);
        primaryStage.show();

    }

    private class MyContextMenu extends ContextMenu {

        public MyContextMenu(Label label) {

            MenuItem item = new MenuItem("copy to text field");
            item.setOnAction(event -> {

                // I want to copy the text of the Label I clicked to TextField
                text.setText(label.getText());

                event.consume();
            });

            getItems().add(item);

        }

    }
}

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