JAVAFX 如何让文本框生成行数并显示在左侧

您可以使用JavaFX的TextFlow和Text组件来实现带有行号的文本框。以下是一个简单的示例代码：

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.TextArea;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.scene.text.Text;
import javafx.scene.text.TextFlow;
import javafx.stage.Stage;

public class LineNumberTextArea extends Application {

    private static final int DEFAULT_FONT_SIZE = 12;
    private static final String DEFAULT_FONT_FAMILY = "Monospaced";
    private static final int DEFAULT_INSETS = 5;

    @Override
    public void start(Stage primaryStage) throws Exception {
        // Create a TextFlow to hold the line numbers and text
        TextFlow textFlow = new TextFlow();
        textFlow.setPadding(new Insets(DEFAULT_INSETS));

        // Create a ScrollPane to hold the TextFlow
        ScrollPane scrollPane = new ScrollPane();
        scrollPane.setContent(textFlow);

        // Create a VBox to hold the ScrollPane and line numbers
        VBox vBox = new VBox();
        vBox.getChildren().addAll(createLineNumbers(textFlow), scrollPane);

        // Create a BorderPane to hold the VBox
        BorderPane borderPane = new BorderPane();
        borderPane.setCenter(vBox);

        // Create a Scene with the BorderPane
        Scene scene = new Scene(borderPane, 400, 300);

        // Show the Scene
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private TextArea createTextArea() {
        TextArea textArea = new TextArea();
        textArea.setPadding(new Insets(DEFAULT_INSETS));
        textArea.setFont(Font.font(DEFAULT_FONT_FAMILY, DEFAULT_FONT_SIZE));
        return textArea;
    }

    private VBox createLineNumbers(TextFlow textFlow) {
        // Create a VBox to hold the line numbers
        VBox vBox = new VBox();

        // Create a Text object for each line number
        for (int i = 1; i <= 25; i++) {
            Text text = new Text(String.format("%2d", i) + " | ");
            text.setFont(Font.font(DEFAULT_FONT_FAMILY, DEFAULT_FONT_SIZE));
            textFlow.getChildren().add(text);
        }

        // Set the width of the VBox to accommodate the line numbers
        Label label = new Label(" ");
        label.setFont(Font.font(DEFAULT_FONT_FAMILY, DEFAULT_FONT_SIZE));
        vBox.getChildren().add(label);
        vBox.setPrefWidth(label.prefWidth(DEFAULT_FONT_SIZE) * 4);

        // Return the VBox
        return vBox;
    }

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

这个示例代码会创建一个带有行号的文本框，行号会显示在左侧。您可以将其作为参考来实现您自己的需求。