/*
这是一个按钮点击改变面板背景颜色的事件,我做了个监听器,同时监听三个不同的按钮.接收按钮上颜色的文字,比如buttonBlue,按钮文字是BLUE,然后用panelObj.setBackground(Color Color.valueOf(source.getName()));语句处理背景颜色.系统提示需要')'
请帮我看看*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;public class changecolor extends JFrame
{
static JFrame frameObj;
static JPanel panelObj;
JButton buttonBlue;
JButton buttonRed;
JButton buttonYellow;
public void init()
{
frameObj = new JFrame("ChangeBackcolor");
panelObj = new JPanel();
frameObj.getContentPane().add(panelObj);
buttonBlue = new JButton("Blue");
buttonRed = new JButton("Red");
buttonYellow = new JButton("Yellow");
buttonlistener bl = new buttonlistener();
buttonBlue.addActionListener(bl);
buttonRed.addActionListener(bl);
buttonYellow.addActionListener(bl);
panelObj.add(buttonBlue);
panelObj.add(buttonRed);
panelObj.add(buttonYellow);
frameObj.setSize(200,200);
frameObj.setVisible(true);
}
public static void main(String args[])
{
new changecolor().init();
}
public class buttonlistener implements ActionListener
{
public void actionPerformed(ActionEvent evt)
{
JButton source = (JButton)evt.getSource();
panelObj.setBackground(Color Color.valueOf(source.getName()));
}
}
}
这是一个按钮点击改变面板背景颜色的事件,我做了个监听器,同时监听三个不同的按钮.接收按钮上颜色的文字,比如buttonBlue,按钮文字是BLUE,然后用panelObj.setBackground(Color Color.valueOf(source.getName()));语句处理背景颜色.系统提示需要')'
请帮我看看*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;public class changecolor extends JFrame
{
static JFrame frameObj;
static JPanel panelObj;
JButton buttonBlue;
JButton buttonRed;
JButton buttonYellow;
public void init()
{
frameObj = new JFrame("ChangeBackcolor");
panelObj = new JPanel();
frameObj.getContentPane().add(panelObj);
buttonBlue = new JButton("Blue");
buttonRed = new JButton("Red");
buttonYellow = new JButton("Yellow");
buttonlistener bl = new buttonlistener();
buttonBlue.addActionListener(bl);
buttonRed.addActionListener(bl);
buttonYellow.addActionListener(bl);
panelObj.add(buttonBlue);
panelObj.add(buttonRed);
panelObj.add(buttonYellow);
frameObj.setSize(200,200);
frameObj.setVisible(true);
}
public static void main(String args[])
{
new changecolor().init();
}
public class buttonlistener implements ActionListener
{
public void actionPerformed(ActionEvent evt)
{
JButton source = (JButton)evt.getSource();
panelObj.setBackground(Color Color.valueOf(source.getName()));
}
}
}
{
public void actionPerformed(ActionEvent evt)
{
if(evt.getSource() == buttonBlue)
{
panelObj.setBackground(Color.blue);
}
else if(evt.getSource() == buttonRed
{
panelObj.setBackground(Color.red);}
else if(evt.getSource() == buttonYellow
{
panelObj.setBackground(Color.yellow);}
)
}
}
}
就可以了