1.按钮动作事件
单击按钮时触发动作事件，ActionEvent(动作事件） 需要为按钮添加事件监听器——编写动作事件监听器通过实现 ActionListener监听接口来完成。 ActionListener中只需要实现actionPerformed方法，将触发时间后要执行的程序都写在actionPerformed中。
import javax
.swing
.*
;
import java
.awt
.event
.*
;
public class Swing1 extends JFrame
{
int i
=0;
JPanel jp
=new JPanel();
JButton jb
= new JButton("按钮");
public Swing1()
{
this.setTitle("创建面板");
jp
.add(jb
);
jb
.setMnemonic('F');
jb
.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e
)
{
Swing1
.this.jb
.setText("次数："+(++i
));
}
}
);
this.add(jp
);
this.setBounds(300,250,500,200);
this.setVisible(true);
}
public static void main(String
[] args
)
{
Swing1 s1
=new Swing1();
}
}
运行结果：
2.1. 同一个事件注册多个监听器
import javax
.swing
.*
;
import java
.awt
.event
.*
;
public class Swing1 extends JFrame
{
int i
=0;
JPanel jp
=new JPanel();
JButton jb
= new JButton("按钮");
public Swing1()
{
this.setTitle("创建面板");
jp
.add(jb
);
jb
.setMnemonic('F');
jb
.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e
)
{
Swing1
.this.jb
.setText("次数1："+(++i
));
}
}
);
jb
.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e
)
{
Swing1
.this.jb
.setText("次数2："+(++i
));
}
}
);
this.add(jp
);
this.setBounds(300,250,500,200);
this.setVisible(true);
}
public static void main(String
[] args
)
{
Swing1 s1
=new Swing1();
}
}
运行结果：
2.2. 同一个监听器注册给多个事件源
import javax
.swing
.*
;
import java
.awt
.event
.*
;
public class Swing2 extends JFrame implements ActionListener
{
int i
=0;
int j
=0;
JPanel jp
=new JPanel();
JButton jb1
= new JButton("按钮1");
JButton jb2
= new JButton("按钮2");
public Swing2()
{
this.setTitle("创建面板");
jp
.add(jb1
);
jp
.add(jb2
);
jb1
.setMnemonic('N');
jb2
.setMnemonic('F');
jb1
.addActionListener(this);
jb2
.addActionListener(this);
this.add(jp
);
this.setBounds(300,250,500,200);
this.setVisible(true);
}
public void actionPerformed(ActionEvent e
)
{
if(e
.getSource()==jb2
)
{
Swing2
.this.jb2
.setText("按钮2次数："+(++j
));
}
else if(e
.getSource()==jb1
)
{
Swing2
.this.jb1
.setText("按钮1次数："+(++i
));
}
}
public static void main(String
[] args
)
{
Swing2 s1
=new Swing2();
}
}
3. 窗体获取和失去焦点事件
通过WindowFocusListener 监听接口实现
import javax
.swing
.*
;
import java
.awt
.event
.*
;
public class Swing2 extends JFrame implements WindowFocusListener
{
int i
=0;
int j
=0;
JPanel jp
=new JPanel();
JButton jb1
= new JButton("按钮1");
public Swing2()
{
this.setTitle("创建面板");
this.addWindowFocusListener(this);
this.setBounds(300,250,500,200);
this.setVisible(true);
jp
.add(jb1
);
jb1
.setMnemonic('N');
this.add(jp
);
}
public void windowGainedFocus(WindowEvent e
)
{
System
.out
.println("窗体获取焦点");
}
public void windowLostFocus(WindowEvent e
)
{
System
.out
.println("窗体失去焦点");
}
public static void main(String
[] args
)
{
Swing2 s1
=new Swing2();
}
}
4. 窗体打开、关闭和激活事件
WindowListener接口
import javax
.swing
.*
;
import java
.awt
.event
.*
;
public class Swing2 extends JFrame implements WindowListener
{
int i
=0;
int j
=0;
JPanel jp
=new JPanel();
JButton jb1
= new JButton("按钮1");
public Swing2()
{
this.setTitle("创建面板");
this.setBounds(300,250,500,200);
this.setVisible(true);
this.addWindowListener(this);
jp
.add(jb1
);
jb1
.setMnemonic('N');
this.add(jp
);
}
public void windowOpened(WindowEvent e
)
{
System
.out
.println("窗体首次变为可见");
}
public void windowClosing(WindowEvent e
)
{
System
.out
.println("关闭窗体");
}
public void windowClosed(WindowEvent e
)
{
System
.out
.println("关闭窗体后");
}
public void windowIconified(WindowEvent e
)
{
System
.out
.println("从正常状态变为最小化状态");
}
public void windowDeiconified(WindowEvent e
)
{
System
.out
.println("从最小化状态变为正常状态");
}
public void windowActivated(WindowEvent e
)
{
System
.out
.println("窗体被激活");
}
public void windowDeactivated(WindowEvent e
)
{
System
.out
.println("窗体变为非激活");
}
public static void main(String
[] args
)
{
Swing2 s1
=new Swing2();
}
}
运行结果：
窗体被激活
窗体首次变为可见
从正常状态变为最小化状态
窗体变为非激活
从最小化状态变为正常状态
窗体被激活
关闭窗体
窗体变为非激活
5. 密码框
import javax
.swing
.*
;
import java
.awt
.*
;
import java
.awt
.event
.*
;
public class KongJian extends JFrame implements ActionListener
{
JTextField jtf
=new JTextField(10);
JPasswordField jpf
=new JPasswordField(10);
JLabel jl1
=new JLabel("用户名：");
JLabel jl2
=new JLabel("密码：");
JButton jb
=new JButton("提交");
JLabel j1
=new JLabel();
JPanel jp
=new JPanel();
public KongJian()
{
this.setTitle("创建文本框");
jp
.setLayout(null
);
jl1
.setBounds(30,20,80,30);
jp
.add(jl1
);
jl2
.setBounds(30,70,80,30);
jp
.add(jl2
);
jtf
.setBounds(80,20,180,30);
jp
.add(jtf
);
jpf
.setBounds(80,70,180,30);
jp
.add(jpf
);
jb
.setBounds(50,130,80,30);
jp
.add(jb
);
j1
.setBounds(10,180,300,30);
jp
.add(j1
);
jb
.addActionListener(this);
this.add(jp
);
this.setBounds(300,250,350,250);
this.setVisible(true);
}
@SuppressWarnings("deprecation")
public void actionPerformed(ActionEvent e
)
{
String s1
=jtf
.getText();
String s2
=jpf
.getText();
j1
.setText("你的用户名为："+s1
+" 密码为："+s2
);
}
public static void main(String
[] args
)
{
KongJian kj
= new KongJian();
}
}
6.多行文本框
import javax
.swing
.*
;
public class DuoHang extends JFrame
{
JTextArea jta
=new JTextArea(6,10);
JLabel j1
=new JLabel("多行文本框");
JPanel jp
=new JPanel();
public DuoHang()
{
this.setTitle("创建文本框");
jp
.add(jta
);
jp
.add(j1
);
this.add(jp
);
this.setBounds(300,250,300,200);
this.setVisible(true);
}
public static void main(String
[] args
)
{
DuoHang dh
=new DuoHang();
}
}
