代码如下：
[code=Java][/code]
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class login{
JLabel JLabel1,JLabel2;
JFrame mainJFrame;
Container con;
JButton loginbtn,cancelbtn;
JTextField userText;
JTextField passwordField;
HandleAction handleAction;
public class HandleAction implements ActionListener{
public void actionPerformed(ActionEvent e){
String msg;
if(e.getSource()==loginbtn){
msg="your username:"+userText.getText()+"\n your password:"
+new String(passwordField.getText());
JOptionPane.showMessageDialog(mainJFrame,msg);
}
else if(e.getSource()==cancelbtn){
passwordField.setText("");
userText.setText("");
}
}
}
public login(){
handleAction=new HandleAction();
JLabel1=new JLabel("用户名");
JLabel2=new JLabel("密码");
mainJFrame=new JFrame("后台登陆");
con=mainJFrame.getContentPane();
loginbtn=new JButton("登陆");
loginbtn.addActionListener(handleAction);
cancelbtn=new JButton("取消");
cancelbtn.addActionListener(handleAction);
userText=new JTextField();
userText.setColumns(20);
passwordField=new JPasswordField();
passwordField.setColumns(20);
con.add(JLabel1);
con.add(userText);
con.add(JLabel2);
con.add(passwordField);
con.add(loginbtn);
con.add(cancelbtn);
mainJFrame.setSize(300,300);
mainJFrame.setVisible(true);
mainJFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args){new login();}
}
但是运行后结果：是所有的标签和按钮都叠加到了一起，本人初学java求大神指教。
------解决方案--------------------------------------------------------
那是因为con默认的布局是BorderLayout，直接给你代码：
- Java code
import javax.swing.*;import java.awt.event.*;import java.awt.*;public class HandleAction implements ActionListener{ JLabel JLabel1,JLabel2; JFrame mainJFrame; Container con; JButton loginbtn,cancelbtn; JTextField userText; JTextField passwordField; public void actionPerformed(ActionEvent e){ String msg; if(e.getSource()==loginbtn){ msg="your username:"+userText.getText()+"\n your password:" +new String(passwordField.getText()); JOptionPane.showMessageDialog(mainJFrame,msg); } else if(e.getSource()==cancelbtn){ passwordField.setText(""); userText.setText(""); }} public HandleAction(){ JLabel1=new JLabel("用户名"); JLabel1.setBounds(new Rectangle(20,20,60,20));//设置位置左边距、上边距、宽度、高度 JLabel2=new JLabel("密码"); JLabel2.setBounds(new Rectangle(20,50,60,20));//设置位置左边距、上边距、宽度、高度 mainJFrame=new JFrame("后台登陆"); con=mainJFrame.getContentPane(); con.setLayout(null);//要设置成null,不然默认是BorderLayout布局 loginbtn=new JButton("登陆"); loginbtn.setBounds(new Rectangle(20,80,60,20));//设置位置左边距、上边距、宽度、高度 loginbtn.addActionListener(this); cancelbtn=new JButton("取消"); cancelbtn.setBounds(new Rectangle(90,80,60,20));//设置位置左边距、上边距、宽度、高度 cancelbtn.addActionListener(this); userText=new JTextField(); userText.setColumns(20); userText.setBounds(new Rectangle(90,20,60,20));//设置位置左边距、上边距、宽度、高度 passwordField=new JPasswordField(); passwordField.setColumns(20); passwordField.setBounds(new Rectangle(90,50,60,20));//设置位置左边距、上边距、宽度、高度 con.add(JLabel1); con.add(userText); con.add(JLabel2); con.add(passwordField); con.add(loginbtn); con.add(cancelbtn); mainJFrame.setSize(300,300); mainJFrame.setVisible(true); mainJFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); }public static void main(String[] args){new HandleAction();}}