什么'；“我的程序出了问题，我总是出错”；arrow.java:42:错误：找不到符号；

我目前正在大学学习一些编程课程，我们正在做一项作业，创建一个箭头，它可以通过按键（R或B）和鼠标点击（左右）来改变颜色。我已经进行了大约一个小时的故障排除，我被这一个错误卡住了

“arrow.java:42:错误：找不到符号 SetTitle（“用键或鼠标给箭头上色”）

这是我的代码，如果它也有帮助的话

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.scene.shape.Polygon;
import javafx.scene.input.MouseButton;
import javafx.scene.input.KeyCode;
public class Arrow extends Application {
    @Override // Override the start method in the Application class
    public void start(Stage primaryStage) {
        StackPane pane = new StackPane();
        
        //Create an arrow and place it in the pane
        Polygon arrow = new Polygon();
        arrow.setFill(Color.WHITE);
        arrow.setStroke(Color.BLACK);
        arrow.getPoints().addAll(50.0,50.0, 150.0,50.0, 150.0,0.0, 250.0,100.0, 150.0,200.0, 50.0,150.0);
        pane.getChildren().add(arrow);
        
        //Add a mouse click handler to the arrow
        arrow.setOnMouseClicked(e -> {
            if (e.getButton() == MouseButton.PRIMARY) {
                arrow.setFill(Color.RED);
            }
            else if (e.getButton() == MouseButton.SECONDARY) {
                arrow.setFill(Color.BLUE);
            }
        });
        //Create a scene and place it in the stage
        Scene scene = new Scene(pane, 400, 400);
        scene.setOnKeyPressed (e -> {
            if (e.getCode() == KeyCode.R) {
                arrow.setFill(Color.RED);
            }
            else if (e.getCode() == KeyCode.B) {
                arrow.setFill(Color.BLUE);
            }
        });
        
        primaryStage.SetTitle("Color an Arrow with Key or Mouse"); // Set the stage title
        primaryStage.setScene(scene); //Place the scene in the stage
        primaryStage.show(); //Display the Stage
    }
}

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使用“setTitle”而不是“setTitle”

这是否回答了您的问题？

setTitle

您有一个输入错误，“setTitle”不是setTitle