Java如何实现单击一次鼠标，就在鼠标位置出现一个圆7

发布网友发布时间：2023-09-29 16:58

共4个回答

热心网友时间：2024-04-06 04:12

用JFrame做；

实现重绘repaint方法；

drawCircle方法即可。

例如如下例子：

public class Draw extends JFrame {
private int x, y;
boolean isVisible = false;
public Draw () {
  addHandler();
  setSize(500, 500);
  setLocation(350, 150);
  setVisible(true);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
  new Draw ();
}
private void addHandler() {
  addMouseListener(new MouseAdapter() {
   public void mouseClicked(MouseEvent e) {
    if (e.getButton() == MouseEvent.BUTTON1) {
     x = e.getX();
     y = e.getY();
     isVisible = true;
     repaint();
    } else if (e.getButton() == MouseEvent.BUTTON3) {
     isVisible = false;
     repaint();
    }
   }
  });
}
public void paint(Graphics g) {
  super.paint(g);
  if(isVisible){
   g.setColor(Color.red);
   g.drawOval(x, y, 100, 100);
  }
}
}

热心网友时间：2024-04-06 04:13

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;

public class TEST5 extends JFrame {
// x,y坐标
private int x, y;
//控制显示
boolean isVisible = false;

public TEST5() {
addHandler();
setSize(500, 500);
setLocation(350, 150);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args) {
new TEST5();
}

private void addHandler() {
addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
// 左键
if (e.getButton() == MouseEvent.BUTTON1) {
x = e.getX();
y = e.getY();
isVisible = true;
repaint();
} else if (e.getButton() == MouseEvent.BUTTON3) {// 右键
isVisible = false;
repaint();
}

}

});
}
public void paint(Graphics g) {
super.paint(g);
if(isVisible){
g.setColor(Color.red);
g.drawOval(x, y, 100, 100);
}
}
}

热心网友时间：2024-04-06 04:10

捕捉鼠标位置，当点击事件触发时，draw一个圆

热心网友时间：2024-04-06 04:15

import java.util.*;
import java.awt.*;
import java.awt.event.*;
public class TestPoint {
public static void main(String[] args) {
  new MyFrame().launch();
}
}
class MyFrame extends Frame {
ArrayList<Point> c = null;
public void launch() {
  c = new ArrayList<Point>();
  addMouseListener(new Monitor());
  setBounds(300,300,400,400);
  setVisible(true);
  this.addWindowListener(new WindowAdapter() {
   public void windowClosing(WindowEvent e) {
    System.exit(0);
   }
  });
}

public void addPoint(Point p) {
  c.add(p);
}

public void paint(Graphics g) {
  Iterator<Point> i = c.iterator();
  while(i.hasNext()) {
   Point p = i.next();
   g.fillOval(p.x, p.y, 10, 10);
  }
}

private class Monitor extends MouseAdapter {
  public void mousePressed(MouseEvent e) {
   Point p = new Point(e.getX(), e.getY());
   MyFrame f = (MyFrame)e.getSource();
   f.addPoint(p);
   f.repaint();
  }
}
}