Java 对象在调整大小和最小化窗口时消失
我需要一些关于这个代码的帮助。 我已经有了绘制对象和清除窗口中对象的功能,但是当我调整大小或最小化窗口时,对象不会消失,我如何做到这一点 这是我目前掌握的代码:Java 对象在调整大小和最小化窗口时消失,java,java-2d,Java,Java 2d,我需要一些关于这个代码的帮助。 我已经有了绘制对象和清除窗口中对象的功能,但是当我调整大小或最小化窗口时,对象不会消失,我如何做到这一点 这是我目前掌握的代码: public class miClass implements ActionListener{ JFrame ventana; JPanel panel; JButton p,c; Graphics g; Image img; Font font1,font2,font3; public miClass(){ ventana
public class miClass implements ActionListener{
JFrame ventana;
JPanel panel;
JButton p,c;
Graphics g;
Image img;
Font font1,font2,font3;
public miClass(){
ventana = new JFrame("Aplicacion.");
p = new JButton("P");
c = new JButton("C");
panel = new JPanel();
ventana.setLayout(null);
ventana.setBounds(100,100,600,600);
ventana.getContentPane().add(panel);
ventana.add(p);
p.addActionListener(this);
c.addActionListener(this);
p.setBounds(20,20,120,45);
ventana.add(c);
c.setBounds(200,20,120,45);
ventana.setFocusable(true);
ventana.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ventana.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
g = ventana.getGraphics();
Toolkit tool = Toolkit.getDefaultToolkit();
img = tool.getImage("prueba.png");
g.drawImage(img,0,100,null);
font1 = new Font("Helvetica",Font.PLAIN,22);
g.setFont(font1);
g.drawString("Hola", 100, 300);
font2 = new Font("TimesRoman",Font.BOLD,20);
g.setFont(font2);
g.drawString("Mundo", 100, 340);
font3 = new Font("Courier",Font.BOLD+Font.ITALIC,25);
g.setFont(font3);
g.drawString("WASAAAA!", 100, 400);
g.setColor(Color.green);
g.drawOval(300, 200, 150, 100);
g.setColor(Color.red);
g.drawArc(200, 400, 250, 64, 135, 46);
g.setColor(Color.blue);
g.drawLine(400, 200, 150, 100);
g.setColor(Color.magenta);
g.drawRect(300, 250, 160, 50);
g.setColor(Color.cyan);
g.fillRect(100,400,20,240);
g.setColor(Color.lightGray);
g.fillOval(100,340,14,30);
if(e.getSource() == c){ //Clean all objects on the window//
g.clearRect(0,100,900,800);
}
}
public static void main(String args[]){
miClass GUI = new miClass();
}
}
调整帧大小时,帧将重置为其初始状态,并且代码仅在单击按钮时重绘,而不是在调整其大小时重绘。在调整父帧的大小后,将调用组件的任何子类上的paintComponent方法,因此可以通过重写该方法来解决此问题
package SO;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class miClass implements ActionListener {
JFrame ventana;
JPanel panel;
JButton p, c;
Graphics g;
Image img;
Font font1, font2, font3;
public miClass() {
ventana = new JFrame("Aplicacion.");
p = new JButton("P");
c = new JButton("C");
panel = new JPanel() {
@Override
public void paintComponent(Graphics g) {
// your stuff
font1 = new Font("Helvetica", Font.PLAIN, 22);
g.setFont(font1);
g.drawString("THIS GETS REDRAWN", 100, 300);
}
};
panel.setSize(400, 400);
ventana.setLayout(null);
ventana.setBounds(100, 100, 600, 600);
ventana.getContentPane().add(panel);
ventana.add(p);
p.addActionListener(this);
c.addActionListener(this);
p.setBounds(20, 20, 120, 45);
ventana.add(c);
c.setBounds(200, 20, 120, 45);
ventana.setFocusable(true);
ventana.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ventana.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
g = panel.getGraphics();
Toolkit tool = Toolkit.getDefaultToolkit();
img = tool.getImage("prueba.png");
g.drawImage(img, 0, 100, null);
font1 = new Font("Helvetica", Font.PLAIN, 22);
g.setFont(font1);
g.drawString("Hola", 100, 300);
font2 = new Font("TimesRoman", Font.BOLD, 20);
g.setFont(font2);
g.drawString("Mundo", 100, 340);
font3 = new Font("Courier", Font.BOLD + Font.ITALIC, 25);
g.setFont(font3);
g.drawString("WASAAAA!", 100, 400);
g.setColor(Color.green);
g.drawOval(300, 200, 150, 100);
g.setColor(Color.red);
g.drawArc(200, 400, 250, 64, 135, 46);
g.setColor(Color.blue);
g.drawLine(400, 200, 150, 100);
g.setColor(Color.magenta);
g.drawRect(300, 250, 160, 50);
g.setColor(Color.cyan);
g.fillRect(100, 400, 20, 240);
g.setColor(Color.lightGray);
g.fillOval(100, 340, 14, 30);
if (e.getSource() == c) { // Clean all objects on the window//
g.clearRect(0, 100, 900, 800);
}
}
public static void main(String args[]) {
miClass GUI = new miClass();
}
}
感谢您的回答,还有一个问题,我可以用这个组件和JButton或actionPerformed一起使用吗?您可以从actionPerformed调用panel.repaint()。repaint()将依次调用paintComponent。