Question

我有这个程序，每次点击画一个圆圈，我的问题是当我点击其他地方时它会擦除圆圈。如何让程序保持圆圈而不删除前一个？我还想创建一个擦除所有圆圈的按钮，是否有方法可以删除所有内容？

import javax.swing.JPanel;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Random;

public class CircleObj extends JPanel {
    private int rColor;
    private int gColor;
    private int bColor;
    private int radius;
    private Random rand = new Random();
    private int xStart;
    private int yStart;
    ArrayList <Circle> xxx ;

    public CircleObj () {
    xxx =  new ArrayList<Circle>();

    addMouseListener(new MouseAdapter() {

        public void mouseClicked (MouseEvent e) {

        xStart = e.getX();
        yStart = e.getY();
        rColor = rand.nextInt(256);
        gColor = rand.nextInt(256);
        bColor = rand.nextInt(256);
        radius = rand.nextInt(100);
        xxx.add(new Circle(xStart, yStart,rColor, gColor, bColor, radius));
        System.out.println(xxx);
        repaint();
        }
    }); // end addMouseListener

    }

    public void paintComponent (Graphics g) {
    super.paintComponent(g);
    g.setColor(new Color(rColor, gColor, bColor));
    g.fillOval(xStart, yStart, radius, radius);

    }

     class Circle {
        private int x;
        private int y;
        private int rad;
        private int rcol;
        private int gcol;
        private int bcol;

        public Circle (int xValue, int yValue,int redValue, int greenValue, int blueValue, int radValue) {

            x = xValue;
            y = yValue;
            rad = radValue;
            rcol = redValue;
            gcol = greenValue;
            bcol = blueValue;
            }


        public String toString (){

        return String.format("X value is: " + x + "\nY value is: " + y + "\nRadius value is: " +rad +
                   "\nRed value is: "+ rcol+ "\nGreen value is: "+ gcol + "\nBlue value is: "+bcol+ "\n\n");

        }

    }

}

Answer 1

你有一个圆圈列表，看起来对我不熟 - 每当你点击你添加一个圆圈但你只画一个圆圈你点击...

public void paintComponent (Graphics g) {
    super.paintComponent(g);
    //g.setColor(new Color(rColor, gColor, bColor));
    //g.fillOval(xStart, yStart, radius, radius);
    for (Circle circle: xxx){
        g.setColor(new Color(circle.rcol, circle.gcol, circle.bcol));
        g.fillOval(circle.x, circle.y, circle.rad, circle.rad);
    }
}

使用此方法为您的屏幕添加圈子 - 如果您想删除它们，按钮或任何其他活动，请拨打清除列表的xxx.clear()（不要忘记{{1}清除清单后......

绘制对象并擦除它们

1 个答案: