在JavaFX中将节点添加到TreeItem

Question

我有一个TreeItem<String>对象.

我想在其中放一个按钮.

Button button = new Button("Hello!");
root.setGraphic(button);  // root is the TreeItem object

还不错,但我想自由定位这个按钮.我想要"Root"的权利.

更改按钮的布局X似乎没有做任何事情.那怎么办呢？

Answer 1

您可以使用Label和Button初始化创建自定义类扩展HBox类并包含构造函数声明.接下来,您可以使用此类来指定TreeView<T>和TreeItem<T>泛型类型.这种简单的HBox自定义类的示例如下所示:

import javafx.geometry.Pos;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.HBox;

public class CustomItem extends HBox {

    private Label boxText;
    private Button boxButton;

    CustomItem(Label txt) {
        super();

        this.boxText = txt;

        this.getChildren().add(boxText);
        this.setAlignment(Pos.CENTER_LEFT);
    }

    CustomItem(Label txt, Button bt) {
        super(5);

        this.boxText = txt;
        this.boxButton = bt;

        this.getChildren().addAll(boxText, boxButton);
        this.setAlignment(Pos.CENTER_LEFT);
    }
}

在实践中使用它可能如下所示:

import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class TreeViewDemo extends Application {

    public Parent createContent() {

        /* layout */
        BorderPane layout = new BorderPane();

        /* layout -> center */

        /* initialize TreeView<CustomItem> object */
        TreeView<CustomItem> tree = new TreeView<CustomItem>();

        /* initialize tree root item */
        TreeItem<CustomItem> root = new TreeItem<CustomItem>(new CustomItem(new Label("Root")));

        /* initialize TreeItem<CustomItem> as container for CustomItem object */
        TreeItem<CustomItem> node = new TreeItem<CustomItem>(new CustomItem(new Label("Node 1"), new Button("Button 1")));

        /* add node to root */
        root.getChildren().add(node);

        /* set tree root */
        tree.setRoot(root);

        /* add items to the layout */
        layout.setCenter(tree);
        return layout;
    }

    @Override
    public void start(Stage stage) throws Exception {
        stage.setScene(new Scene(createContent()));
        stage.setWidth(200);
        stage.setHeight(200);
        stage.show();
    }

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

效果将如下所示: