java – 单击JButton显示图像
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内容图文
我有个问题.我不知道如何通过单击JButton来显示图像.
我有一个可以显示和隐藏图像的类：
/**
*
*/
package com.samples;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
/**
* @author
*
*/
public class New2 extends JFrame implements ActionListener {
private static String SHOW_ACTION = "show";
private static String HIDE_ACTION = "hide";
private Image image = null;
private boolean showImage = false;
public New2(String filename) {
setTitle("MyWindow");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(800, 600);
this.image = new ImageIcon("..//src/img/Ster.png").getImage();
Container container = getContentPane();
container.setLayout(new BorderLayout());
container.add(createControls(), BorderLayout.SOUTH);
}
private JPanel createControls() {
JButton showButton = new JButton("Show");
showButton.addActionListener(this);
showButton.setActionCommand(SHOW_ACTION);
JButton hideButton = new JButton("Hide");
hideButton.addActionListener(this);
hideButton.setActionCommand(HIDE_ACTION);
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
panel.add(showButton);
panel.add(hideButton);
return panel;
}
@Override
public void paint(Graphics g) {
super.paint(g);
if (showImage) {
g.drawImage(image, 100, 200, image.getWidth(null), image.getHeight(null), null);
}
}
@Override
public void actionPerformed(ActionEvent event) {
String actionCommand = event.getActionCommand();
if (SHOW_ACTION.equals(actionCommand)) {
showImage = true;
} else if (HIDE_ACTION.equals(actionCommand)) {
showImage = false;
}
repaint();
}
/**
* @param args
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
New2 frame = new New2("resources/image.jpg");
frame.setVisible(true);
}
});
}
}
我正在使用MVC,所以我想在控制器的地图中使用JButton的代码,但我不知道如何做到这一点.
package View;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Image;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import Controller.HomeController;
import Controller.KeeperController;
public class Selectie extends JFrame{
private JLabel label, label1, label2;
private JButton keeper;
private JPanel panel;
private Container window = getContentPane();
private KeeperController controller;
public Selectie()
{
initGUI();
}
public void initGUI()
{
setLayout(null);
setTitle();
setSize(800,600);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
label = new JLabel();
label.setBounds(0, 0, 266, 800);
label.setBackground(Color.RED);
label.setOpaque(true);
window.add(label);
label1 = new JLabel();
label1.setBounds(266, 0, 266, 800);
label1.setBackground(Color.BLACK);
label1.setOpaque(true);
window.add(label1);
label2 = new JLabel();
label2.setBounds(532, 0, 266, 800);
label2.setBackground(Color.RED);
label2.setOpaque(true);
window.add(label2);
keeper = new JButton("1. "+""+" Kenneth Vermeer");
keeper.setBounds(60, 500, 200, 25);
keeper.setFocusable(false);
keeper.setBorderPainted(false);
keeper.setContentAreaFilled(false);
keeper.setFont(new Font("Arial",Font.PLAIN,17));
label.add(keeper);
}
}
按钮保持器需要在单击时显示图像.
解决方法:
同样地说,其他人总是使用JLabel来显示图像.这样,很容易在需要时添加/删除它们,而不是绘画.此外,在你的代码中你覆盖了paint(…),对于Swing,我们更喜欢覆盖相应JComponent的paintComponent(…)方法,如果所述组件有一个.
在这里尝试这个代码,我已经分离了Controller部分,你可能会对如何做事情有所了解：
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.WindowConstants;
/**
* @author
*
*/
public class New2 extends JFrame
{
private static String SHOW_ACTION = "show";
private static String HIDE_ACTION = "hide";
public New2(String filename)
{
setTitle("MyWindow");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(800, 600);
Container container = getContentPane();
container.setLayout(new BorderLayout());
container.add(createControls(), BorderLayout.CENTER);
}
private JPanel createControls()
{
JButton showButton = new JButton("Show");
showButton.setActionCommand(SHOW_ACTION);
JButton hideButton = new JButton("Hide");
hideButton.setActionCommand(HIDE_ACTION);
JLabel imageLabel = new JLabel();
New2Controller n2c = new New2Controller(showButton
, hideButton, imageLabel);
showButton.addActionListener(n2c);
hideButton.addActionListener(n2c);
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
panel.add(imageLabel);
panel.add(showButton);
panel.add(hideButton);
return panel;
}
/**
* @param args
*/
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
@Override
public void run()
{
New2 frame = new New2("/img/image.jpg");
frame.setVisible(true);
}
});
}
}
class New2Controller implements ActionListener
{
private JButton showButton;
private JButton hideButton;
private JLabel imageLabel;
private static String SHOW_ACTION = "show";
private static String HIDE_ACTION = "hide";
private Icon infoIcon = UIManager.getIcon("OptionPane.informationIcon");
public New2Controller(JButton show, JButton hide, JLabel label)
{
showButton = show;
hideButton = hide;
imageLabel = label;
}
public void actionPerformed(ActionEvent event)
{
String actionCommand = event.getActionCommand();
if (SHOW_ACTION.equals(actionCommand))
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
imageLabel.setIcon(infoIcon);
}
});
}
else if (HIDE_ACTION.equals(actionCommand))
{
imageLabel.setIcon(null);
}
}
}
此代码表示您使用ImageIO和URL阅读的方式,
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import javax.imageio.ImageIO;
/**
?* @author
?*
?*/
public class New2 extends JFrame
{
? ? private static String SHOW_ACTION = "show";
? ? private static String HIDE_ACTION = "hide";
? ? public New2(String filename)?
{
? ? ? ? setTitle("MyWindow");
? ? ? ? setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
? ? ? ? setSize(800, 600); ? ? ? ?
? ? ? ? Container container = getContentPane();
? ? ? ? container.setLayout(new BorderLayout());
? ? ? ? container.add(createControls(), BorderLayout.CENTER);
? ? }
? ? private JPanel createControls()?
{
? ? ? ? JButton showButton = new JButton("Show"); ? ? ? ?
? ? ? ? showButton.setActionCommand(SHOW_ACTION);
? ? ? ? JButton hideButton = new JButton("Hide"); ? ? ? ?
? ? ? ? hideButton.setActionCommand(HIDE_ACTION);
JLabel imageLabel = new JLabel();
New2Controller n2c = new New2Controller(showButton
, hideButton, imageLabel);
showButton.addActionListener(n2c);
hideButton.addActionListener(n2c);
JPanel panel = new JPanel();
? ? ? ? panel.setLayout(new FlowLayout(FlowLayout.CENTER));
panel.add(imageLabel);
? ? ? ? panel.add(showButton);
? ? ? ? panel.add(hideButton);
? ? ? ? return panel;
? ? }
? ? /**
? ? ?* @param args
? ? ?*/
? ? public static void main(String[] args)?
{
EventQueue.invokeLater(new Runnable()?
{
@Override
public void run()?
{
New2 frame = new New2("/img/image.jpg");
frame.setVisible(true);
}
});
}
}
class New2Controller implements ActionListener
{
private JButton showButton;
private JButton hideButton;
private JLabel imageLabel;
private Image image;
private ImageIcon imageIcon;
private static String SHOW_ACTION = "show";
? ? private static String HIDE_ACTION = "hide";
public New2Controller(JButton show, JButton hide, JLabel label)
{
showButton = show;
hideButton = hide;
imageLabel = label;
try
{
image = ImageIO.read(getClass().getResource("/img/caIcon.png"));
}
catch(Exception e)
{
e.printStackTrace();
}
imageIcon = new ImageIcon(image);
}
public void actionPerformed(ActionEvent event)
{
String actionCommand = event.getActionCommand();
? ? ? ? if (SHOW_ACTION.equals(actionCommand))?
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
imageLabel.setIcon(imageIcon );
}
});
}?
else if (HIDE_ACTION.equals(actionCommand))?
{
imageLabel.setIcon(null);
? ? ? ? }
}
}
而且,当你使用BorderLayout时,永远不要使用NORTH,EAST,WEST和SOUTH来进行BorderLayout.它们已分别替换为PAGE_START,LINE_START,LINE_END和PAGE_END.
BorderLayout对象有五个区域.这些区域由BorderLayout常量指定：
> PAGE_START
> PAGE_END
> LINESTART
> LINE_END
>中心
版本说明：在JDK 1.4版之前,各个区域的首选名称不同,从指南针的点(例如,顶部区域的BorderLayout.NORTH)到我们在示例中使用的常量的更多版本.我们的示例使用的常量是首选,因为它们是标准的,并使程序能够适应具有不同方向的语言.
目录结构：
Your Project
| |
classes src
| |
img *.class(or package Folder)
现在使用getClass().getResource(“/ img / star.png”);
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