java通过鼠标点击添加/删除

Question

我写了一个程序，用户可以在一个矩形中添加和删除圆圈，当用户左键单击时添加，当用户右键单击时删除，虽然它的添加工作正常，但删除效果不好，例如：当我添加四个圆圈并尝试删除所有圆圈时，其中一些没有移除，我不知道为什么，我很困惑。请帮忙

public class BoundingRectangle extends Application {
@Override
public void start(Stage primaryStage) {
    Pane pane = new Pane();
    ArrayList<Circle> list = new ArrayList<>();

    Rectangle rectangle1 = new Rectangle(10, 10, 175, 80);
    rectangle1.setStroke(Color.BLACK);
    rectangle1.setFill(Color.WHITE);
    Rectangle rectangle2 = new Rectangle(250, 75, 300, 200);
    rectangle2.setStroke(Color.BLACK);
    rectangle2.setFill(Color.WHITE);

    Text text = new Text(20, 33, "INSTRUCTION\n" +
            "Add: Left Click\nRemove: Right Click");

    pane.setOnMouseClicked(e -> {
        if (e.getButton() == MouseButton.PRIMARY) {
            Circle circle = new Circle(e.getX(), e.getY(), 10);
            list.add(circle);
            circle.setStroke(Color.BLACK);
            circle.setFill(Color.WHITE);

           if (circle.getCenterX() - rectangle2.getX() < 10) {
                circle.setCenterX(rectangle2.getX() + 10);
            } 
           else if (circle.getCenterY() - rectangle2.getY() < 10) {
                circle.setCenterY(rectangle2.getY() + 10);
            } 
           else if (rectangle2.getX() + rectangle2.getWidth() -
                    circle.getCenterX() < 10) {
                circle.setCenterX(rectangle2.getX() +  rectangle2.getWidth()  - 10);
            } 
           else if (rectangle2.getY() + rectangle2.getHeight() -
                    circle.getCenterY() < 10) {
                circle.setCenterY(rectangle2.getY() + rectangle2.getHeight() - 10);
            }
                pane.getChildren().add(circle);
        }

        else if (e.getButton() == MouseButton.SECONDARY) {
                for (int i = 0; i < list.size(); i++) {
                    if (list.get(i).contains(e.getX(), e.getY())) {
                        pane.getChildren().remove(list.get(i));
                        list.remove(i);
                        break;
                    }
                }
            }

        });
        pane.getChildren().addAll(rectangle1, rectangle2, text);

        Scene scene = new Scene(pane, 600, 300);
        primaryStage.setScene(scene);
        primaryStage.setTitle("BoundingRectangle");
        primaryStage.show();
    }
}

Answer 1

我认为这看起来像是一个错误：如果在右键单击失败后调整窗口大小，则“调整大小”命令强制的重新绘制会删除圆圈。一些简单的调试显示，圆圈在应该的时候会从窗格的子列表中删除（因此这是一个重新绘制问题）

作为一种解决方法，将第二个矩形替换为窗格。下面是直接替换的代码，没有其他更改：实际上，您可以对其进行大量重构以简化它（例如，将鼠标侦听器注册到第二个窗格而不是第一个窗格以进行添加，并将鼠标侦听器注册到每个圆以进行删除）：

import java.util.ArrayList;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.input.MouseButton;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class BoundingRectangle extends Application {
    @Override
    public void start(Stage primaryStage) {
        Pane pane = new Pane();
        ArrayList<Circle> list = new ArrayList<>();

        Rectangle rectangle1 = new Rectangle(10, 10, 175, 80);
        rectangle1.setStroke(Color.BLACK);
        rectangle1.setFill(Color.WHITE);
        Pane rectangle2 = new Pane();
        rectangle2.relocate(250, 75);
        rectangle2.setPrefSize(300,  200);
        rectangle2.setStyle("-fx-border-color: black;");

        Text text = new Text(20, 33, "INSTRUCTION\n"
                + "Add: Left Click\nRemove: Right Click");

        pane.setOnMouseClicked(e -> {
            if (e.getButton() == MouseButton.PRIMARY) {
                Circle circle = new Circle(e.getX(), e.getY(), 10);
                list.add(circle);
                circle.setStroke(Color.BLACK);
                circle.setFill(Color.WHITE);

                if (circle.getCenterX() - rectangle2.getBoundsInParent().getMinX() < 10) {
                    circle.setCenterX(rectangle2.getBoundsInParent().getMinX() + 10);
                } else if (circle.getCenterY() - rectangle2.getBoundsInParent().getMinY() < 10) {
                    circle.setCenterY(rectangle2.getBoundsInParent().getMinY() + 10);
                } else if (rectangle2.getBoundsInParent().getMaxX()
                        - circle.getCenterX() < 10) {
                    circle.setCenterX(rectangle2.getBoundsInParent().getMaxX() - 10);
                } else if (rectangle2.getBoundsInParent().getMaxY()
                        - circle.getCenterY() < 10) {
                    circle.setCenterY(rectangle2.getBoundsInParent().getMaxY() - 10);
                }
                pane.getChildren().add(circle);
            }

            else if (e.getButton() == MouseButton.SECONDARY) {
                for (int i = 0; i < list.size(); i++) {
                    if (list.get(i).contains(e.getX(), e.getY())) {
                        pane.getChildren().remove(list.get(i));
                        list.remove(i);
                        break;
                    }
                }
            }

        });
        pane.getChildren().addAll(rectangle1, rectangle2, text);

        Scene scene = new Scene(pane, 600, 300);
        primaryStage.setScene(scene);
        primaryStage.setTitle("BoundingRectangle");
        primaryStage.show();
    }

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

这是重构后的版本。由于rectangle2现在是Pane，您可以直接将圆添加到它，而不必担心调整它们的位置。右键单击是在圆圈本身上处理的，因此不需要代码来检查单击是否在圆圈上，因此，不需要单独的圆圈列表（尽管您的实际应用程序可能出于其他原因需要）

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.input.MouseButton;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class BoundingRectangle extends Application {
    @Override
    public void start(Stage primaryStage) {
        Pane pane = new Pane();

        Rectangle rectangle1 = new Rectangle(10, 10, 175, 80);
        rectangle1.setStroke(Color.BLACK);
        rectangle1.setFill(Color.WHITE);

        Pane rectangle2 = new Pane();
        rectangle2.relocate(250, 75);
        rectangle2.setPrefSize(300,  200);
        rectangle2.setStyle("-fx-border-color: black;");

        Text text = new Text(20, 33, "INSTRUCTION\n"
                + "Add: Left Click\nRemove: Right Click");

        rectangle2.setOnMouseClicked(e -> {
            if (e.getButton() == MouseButton.PRIMARY) {
                Circle circle = new Circle(e.getX(), e.getY(), 10);

                circle.setOnMouseClicked(evt -> {
                    if (evt.getButton() == MouseButton.SECONDARY) {
                        rectangle2.getChildren().remove(circle);
                    }
                });

                circle.setStroke(Color.BLACK);
                circle.setFill(Color.WHITE);

                rectangle2.getChildren().add(circle);
            }


        });
        pane.getChildren().addAll(rectangle1, rectangle2, text);

        Scene scene = new Scene(pane, 600, 300);
        primaryStage.setScene(scene);
        primaryStage.setTitle("BoundingRectangle");
        primaryStage.show();
    }

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