Java isRollover()方法在我的swing应用程序中不会产生事件 [英] Java isRollover() method does not produce an event in my swing application
问题描述
我正在阅读一本很棒的书，名为《 Swing:初学者指南》. 书中有这段代码可创建按钮和标签，以提醒按钮状态更改事件:
I am reading a great book called Swing: A Beginner's guide. There is this code in the book that creates a button and a label that alerts on button's state change events :
//Demonstrate a change listener and the button model
package swingexample2_6;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
public class ChangeDemo {
JButton jbtn;
JLabel jlab;
public ChangeDemo() {
//Create a new JFrame container
JFrame jfrm = new JFrame("Button Change Events");
//Specify FlowLayout for the layout manager
jfrm.getContentPane().setLayout(new FlowLayout());
//Give the frame an initial size
jfrm.setSize(250, 160);
//Terminate the program when the user closes the application
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create an empty label
jlab = new JLabel();
//Make a button
jbtn = new JButton("Press for Change Event Test");
//--Add change listener
jbtn.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent ce) {
ButtonModel mod = jbtn.getModel();
String what = "";
if (mod.isEnabled()) {
what += "Enabled<br>";
}
if (mod.isRollover()) {
what += "Rollover<br>";
}
if (mod.isArmed()) {
what += "Armed<br>";
}
if (mod.isPressed()) {
what += "Pressed<br>";
}
//Notice that this label's text is HTML
jlab.setText("<html>Current stats:<br>" + what);
}
});
//Add the components to the content pane
jfrm.getContentPane().add(jbtn);
jfrm.getContentPane().add(jlab);
//Display the frame
jfrm.setVisible(true);
}
public static void main(String[] args) {
//Create the frame on the event dispatching thread
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new ChangeDemo();
}
});
}
}
除翻转事件外，其他所有东西都工作正常. 底层操作系统是Mac OS Lion. 我应该把这个摇摆问题归咎于Lion还是我做错了什么? 谢谢.
Everything is working fine except for the rollover event. The underlying operating system is Mac OS Lion. Should I blame Lion for this swing problem or am I doing something wrong? Thank you.
更新1:我的neatbeans设置图片(希望对您有所帮助)
Update 1 : My neatbeans settings picture (I hope it helps)
推荐答案
在具有Java版本1.6.0_26的Leopard上测试的代码如下所示.后面的</html>标签修复了悬停时的突出故障.
Code as tested on Leopard with Java version 1.6.0_26 shown below. The trailing </html> tag fixed a highlighting glitch on rollover.
附录:使用下面的更新示例，添加setRolloverEnabled(true)可使模型按预期工作.有趣的是，当isRollover()为true时，Mac UI委托com.apple.laf.AquaButtonUI不执行任何操作.如果对您的应用程序很重要，则当以下谓词为true时，您可以采取所需的操作:
Addendum: Using the updated example below, adding setRolloverEnabled(true) allows the model to work as expected. Interestingly, the Mac UI delegate, com.apple.laf.AquaButtonUI, does nothing when isRollover() is true. If it's important to your application, you can take the desired action when the following predicate is true:
System.getProperty("os.name").startsWith("Mac OS X")
作为参考，此示例演示了setRolloverIcon().
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
public class ChangeDemo {
private JButton jbtn;
private JLabel jlab;
public ChangeDemo() {
JFrame jfrm = new JFrame("Button Change Events");
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jfrm.setLayout(new GridLayout(0, 1));
jlab = new JLabel("", JLabel.CENTER);
jbtn = new JButton("Press for Change Event Test");
jbtn.setRolloverEnabled(true);
jbtn.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent ce) {
ButtonModel mod = jbtn.getModel();
String what = "";
if (mod.isEnabled()) {
what += "Enabled<br>";
}
if (mod.isRollover()) {
what += "Rollover<br>";
}
if (mod.isArmed()) {
what += "Armed<br>";
}
if (mod.isPressed()) {
what += "Pressed<br>";
}
//Notice that this label's text is HTML
jlab.setText("<html>Current stats:<br>" + what + "</html>");
}
});
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createEmptyBorder(50, 10, 0, 10));
panel.add(jbtn);
jfrm.add(panel);
jfrm.add(jlab);
jfrm.pack();
jfrm.setLocationRelativeTo(null);
jfrm.setVisible(true);
}
public static void main(String[] args) {
//Create the frame on the event dispatching thread
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ChangeDemo changeDemo = new ChangeDemo();
}
});
}
}
这篇关于Java isRollover()方法在我的swing应用程序中不会产生事件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
