在点击JButton时显示图像 [英] Displaying image on clicking JButton
本文介绍了在点击JButton时显示图像的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我尝试在点击JButton时显示图片,但执行时点击按钮时不显示图片。
Im trying to display an image upon clicking a JButton but upon execution the image is not displayed when button is clicked.
import javax.swing.JButton;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.ImageIcon;
import javax.swing.JApplet;
import java.awt.*;
public class new2 extends JFrame implements ActionListener
{
private boolean b1,b2;
Container contentPane= getContentPane();
JButton awar=new JButton("@war");
JButton arrow=new JButton("arrow");
private Image image1,image2;
public new2()
{
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane.setLayout(new FlowLayout());
awar.addActionListener(this);
contentPane.add(awar).setVisible(true);
arrow.addActionListener(this);
contentPane.add(arrow).setVisible(true);
}
public void init()
{
image1=Toolkit.getDefaultToolkit().getImage("@war.jpeg");
image2=Toolkit.getDefaultToolkit().getImage("arrow.gif");
}
public void paint(Graphics g)
{
if(b1==true)
{
g.drawImage(image1,0,0,this);
}
else if(b2==true)
{
g.drawImage(image2,0,0,this);
}
}
public void actionPerformed(ActionEvent event)
{
String actionCommand = event.getActionCommand();
if(actionCommand.equals("@war"))
{
b1=true;
}
else if(actionCommand.equals("arrow"))
{
b2=true;
}
}
public static void main(String args[])
{
new2 m=new new2();
m.setVisible(true);
}
}
推荐答案
您应该覆盖 JFrame.paint(Graphics g)
方法。
每当你想刷新JFrame实例的内容时调用 JFrame.repaint()
方法。
You should override the JFrame.paint(Graphics g)
method.
Whenever you want to refresh the content of the JFrame instance call the JFrame.repaint()
method.
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