package application; import javafx.application.Application; import javafx.geometry.Pos; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.TextField; import javafx.scene.layout.BorderPane; import javafx.scene.layout.GridPane; import javafx.scene.layout.HBox; import javafx.stage.Stage; public class ACSDHomework3III extends Application { TextField tfA = new TextField(); TextField tfB = new TextField(); TextField tfC = new TextField(); TextField tfD = new TextField(); Button btisDight = new Button(" is Dight "); Button btisNum = new Button(" is Num "); Button bttoUp = new Button(" to Up "); Button bttoLow = new Button(" to Low "); Button btisUp = new Button(" is Up "); @Override public void start(Stage primaryStage) { GridPane gridPane = new GridPane(); gridPane.setHgap(5); gridPane.setVgap(5); gridPane.add(new Label("Class ID:"), 0, 0); gridPane.add(tfA, 1, 0); gridPane.add(new Label("Name:"), 0, 1); gridPane.add(tfB, 1, 1); gridPane.add(new Label("A Character"), 1, 2); gridPane.add(new Label("Result"), 5, 3); gridPane.add(tfC, 1, 4); gridPane.add(tfD, 5, 4); gridPane.setAlignment(Pos.CENTER); tfD.setAlignment(Pos.BOTTOM_RIGHT); HBox hBox = new HBox(btisDight,btisNum,bttoUp,bttoLow,btisUp); hBox.getChildren().addAll(); hBox.setAlignment(Pos.CENTER); BorderPane borderPane = new BorderPane(); borderPane.setCenter(gridPane); borderPane.setBottom(hBox); btisDight.setOnAction(e -> isDight()); btisNum.setOnAction(e -> isNum()); bttoUp.setOnAction(e -> toUp()); bttoLow.setOnAction(e -> toLow()); btisUp.setOnAction(e -> isUp()); Scene scene = new Scene(borderPane, 500, 200); primaryStage.setTitle("William 201045"); primaryStage.setScene(scene); primaryStage.show(); } String C; private void isDight() { tfD = Charater.isDight(tfC.setText); } private void isNum() { tfC.setText((String.format("%.2f",Charater.isNum(C)))); } private void toUp() { tfC.setText((String.format("%.2f",Charater.toUpCase(C)))); } private void toLow() { tfC.setText((String.format("%.2f",Charater.toLowCase(C)))); } private void isUp() { tfC.setText((String.format("%.2f",Charater.isUpCase(C)))); } public static void main(String[] args) { launch(args); } }怎么修改错误的地方

这段代码中有几个错误需要修改：

1. 在 `isDight()` 方法中，应该使用 `tfC.setText()` 而不是 `tfD = Charater.isDight(tfC.setText)`。

2. 在 `isNum()`、`toUp()`、`toLow()`、`isUp()` 方法中，应该使用 `tfC.getText()` 获取文本框中的内容，而不是使用未定义的变量 `C`。

3. 在 `hBox.getChildren().addAll();` 中不应该传入任何参数。

下面是修改后的代码：

package application;

import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class ACSDHomework3III extends Application {

    TextField tfA = new TextField();
    TextField tfB = new TextField();
    TextField tfC = new TextField();
    TextField tfD = new TextField();

    Button btisDight = new Button(" is Dight ");
    Button btisNum = new Button(" is Num ");
    Button bttoUp = new Button(" to Up ");
    Button bttoLow = new Button(" to Low ");
    Button btisUp = new Button(" is Up ");

    @Override
    public void start(Stage primaryStage) {
        GridPane gridPane = new GridPane();
        gridPane.setHgap(5);
        gridPane.setVgap(5);

        gridPane.add(new Label("Class ID:"), 0, 0);
        gridPane.add(tfA, 1, 0);
        gridPane.add(new Label("Name:"), 0, 1);
        gridPane.add(tfB, 1, 1);
        gridPane.add(new Label("A Character"), 1, 2);
        gridPane.add(new Label("Result"), 5, 3);
        gridPane.add(tfC, 1, 4);
        gridPane.add(tfD, 5, 4);

        gridPane.setAlignment(Pos.CENTER);

        tfD.setAlignment(Pos.BOTTOM_RIGHT);

        HBox hBox = new HBox(btisDight, btisNum, bttoUp, bttoLow, btisUp);
        hBox.setAlignment(Pos.CENTER);

        BorderPane borderPane = new BorderPane();
        borderPane.setCenter(gridPane);
        borderPane.setBottom(hBox);

        btisDight.setOnAction(e -> isDight());
        btisNum.setOnAction(e -> isNum());
        bttoUp.setOnAction(e -> toUp());
        bttoLow.setOnAction(e -> toLow());
        btisUp.setOnAction(e -> isUp());

        Scene scene = new Scene(borderPane, 500, 200);
        primaryStage.setTitle("William 201045");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private void isDight() {
        tfD.setText(String.valueOf(Character.isDigit(tfC.getText().charAt(0))));
    }

    private void isNum() {
        tfC.setText(String.valueOf(Character.isDigit(tfC.getText().charAt(0))));
    }

    private void toUp() {
        tfC.setText(String.valueOf(Character.toUpperCase(tfC.getText().charAt(0))));
    }

    private void toLow() {
        tfC.setText(String.valueOf(Character.toLowerCase(tfC.getText().charAt(0))));
    }

    private void isUp() {
        tfC.setText(String.valueOf(Character.isUpperCase(tfC.getText().charAt(0))));
    }

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