java - 使用 MouseListener 和 MouseMotionListener 绘制矩形

Question

我创建了两个包:Display 和 paint_core，其中包含五个 Java 文件:Displayable.java、Drawing。 java、NewColutes.java、OldCitudes.java 和 Main.java。

我面临一些坐标问题，并且输出未按预期输出。我的程序出了什么问题？

Main.java

package paint_core;

import Display.Displayable;

public class Main {

    public Main() {
    }

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

}

Displayable.java

package Display;

import java.awt.Color;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.awt.event.MouseMotionListener;

import javax.swing.JFrame;


public class Displayable extends JFrame implements MouseListener,MouseMotionListener{

    Drawing dr;
    int x,y;
     OldCordinates op;

    public Displayable() 
    {
        setVisible(true);
        dr = new Drawing();

        add(dr);
        dr.addMouseListener(this);
        dr.addMouseMotionListener(this);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public void mouseDragged(MouseEvent e) 
    {

    NewCordinates np = new NewCordinates();

      np.setX(x);
      np.setY(y);
      np.setW(e.getX()-x);
      np.setH(e.getY()-y);

      op= dr.setXY(np.getX(),np.getY(),np.getW(),np.getH(),Color.RED,op);   
    }

    public void mouseMoved(MouseEvent e) 
    {

    }

    public void mouseClicked(MouseEvent e)
    {

    }

    public void mousePressed(MouseEvent e) {
          x=e.getX();
          y=e.getY();
         op = new OldCordinates();
          op.setX(x);
          op.setY(y);
          op.setW(x);
          op.setH(y);
    }

    public void mouseReleased(MouseEvent e) {

    }

    public void mouseEntered(MouseEvent e) {
    }

    public void mouseExited(MouseEvent e) {
    }

}

Drawing.java

package Display;

import java.awt.*;

import java.awt.Color;

import java.awt.Graphics;

import javax.swing.JPanel;

public class Drawing extends JPanel

{

    private int x,y,w,h;
    Color r;
    OldCordinates op;

public OldCordinates setXY(int x,int y,int w,int h,Color r,OldCordinates op)

    {
        this.x = x;
        this.y = y;
        this.w = w;
        this.h = h;
        this.r = r;
        this.op = op;
        //System.out.println("Old Cordinates" + op.getW()+"  "+op.getY());
        repaint();

        op.setH(h);
        op.setW(w);
        //System.out.println("New Cordinates" + w+"  "+h);

        return op;

    }
    @Override
    public void paint(Graphics g) {

       g.drawRect(op.getX(),op.getY(),op.getW(),op.getH());
       g.setColor(r); 
       g.drawRect(x,y,w,h);

    }

}

旧坐标.java

package Display;

import java.awt.*;

import java.awt.Color;

import java.awt.Graphics;

import javax.swing.JPanel;

public class Drawing extends JPanel
{
    private int x,y,w,h;
    Color r;
    OldCordinates op;

    public OldCordinates setXY(int x,int y,int w,int h,Color r,OldCordinates op)

      {
        this.x = x;
        this.y = y;
        this.w = w;
        this.h = h;
        this.r = r;
        this.op = op;
        //System.out.println("Old Cordinates" + op.getW()+"  "+op.getY());
        repaint();

        op.setH(h);
        op.setW(w);
        //System.out.println("New Cordinates" + w+"  "+h);

        return op;

    }
    @Override

    public void paint(Graphics g) {

        //g.drawRect(op.getX(),op.getY(),op.getW(),op.getH());
       g.setColor(r); 
        g.drawRect(x,y,w,h);

    }

}

NewColutes.java

package Display;


public class NewCordinates {
    private int x;
    private int y;
    private int w;
    private int h;

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

    public int getW() {
        return w;
    }

    public void setW(int w) {
        this.w = w;
    }

    public int getH() {
        return h;
    }

    public void setH(int h) {
        this.h = h;
    }


}

Answer 1

您应该重写paintComponent而不是paint。如果这不是您的问题，请提供更多详细信息