本人使用JAVA的时间不长,今天在编程的过程中遇到这个问题请各位高手帮助解决下!~~~~
程序大框如下: import java.awt*;
import java.awt.event.*;
public class ExaMenu extends Frame{
CardLayout myCard;
Panel cPanel;
ExaMenu(){
myCard = new CardLayout();
cPanel = new Panel();
cPanel.setLayout(myCard);
Panel panel1 = new Panel();
Panel panel2 = new Panel();
Panel panel3 = new Panel();
l1=new Label("数a"); l2=new Label("数b");
text1=new TextField(10);
text2=new TextField(10);
text3=new TextField(10);
button1=new Button("加");
panel1.add(l1); panel2.add(text1); panel3.add(l2); cPanel.add(panel1);
cPanel.add(panel2);
cPanel.add(panel3);
add(cPanel,BorderLayout.CENTER);
setSize(500,100);
setVisible(true);
button1.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
double n;
if(e.getSource()==button1){
try{
double n1, n2;
n1=Double.parseDouble(text1.getText());
n1=Double.parseDouble(text1.getText());
n=n1+n2;
text3.setText(String.valueOf(n));
}catch(NumberFormatException ex){
System.out.println("请输入数字!");
}
}
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
}
public static void main(String args[]){
new ExaMenu("Menu");
}
}
一编译就提示:cPanel.add(panel1);这条语句错误!哪位高手能帮助解决一下啊!~~~~~
程序大框如下: import java.awt*;
import java.awt.event.*;
public class ExaMenu extends Frame{
CardLayout myCard;
Panel cPanel;
ExaMenu(){
myCard = new CardLayout();
cPanel = new Panel();
cPanel.setLayout(myCard);
Panel panel1 = new Panel();
Panel panel2 = new Panel();
Panel panel3 = new Panel();
l1=new Label("数a"); l2=new Label("数b");
text1=new TextField(10);
text2=new TextField(10);
text3=new TextField(10);
button1=new Button("加");
panel1.add(l1); panel2.add(text1); panel3.add(l2); cPanel.add(panel1);
cPanel.add(panel2);
cPanel.add(panel3);
add(cPanel,BorderLayout.CENTER);
setSize(500,100);
setVisible(true);
button1.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
double n;
if(e.getSource()==button1){
try{
double n1, n2;
n1=Double.parseDouble(text1.getText());
n1=Double.parseDouble(text1.getText());
n=n1+n2;
text3.setText(String.valueOf(n));
}catch(NumberFormatException ex){
System.out.println("请输入数字!");
}
}
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
}
public static void main(String args[]){
new ExaMenu("Menu");
}
}
一编译就提示:cPanel.add(panel1);这条语句错误!哪位高手能帮助解决一下啊!~~~~~
楼主【sunrise112】截止到2008-07-10 18:04:39的历史汇总数据(不包括此帖):
发帖的总数量:0 发帖的总分数:0 每贴平均分数:0
回帖的总数量:3 得分贴总数量:0 回帖的得分率:0%
结贴的总数量:0 结贴的总分数:0
无满意结贴数:0 无满意结贴分:0
未结的帖子数:0 未结的总分数:0
结贴的百分比:---------------------结分的百分比:---------------------
无满意结贴率:---------------------无满意结分率:---------------------
如何结贴请参考这里:http://topic.csdn.net/u/20080501/09/ef7ba1b3-6466-49f6-9d92-36fe6d471dd1.html
public void add(Component comp,
Object constraints)将指定的组件添加到此容器的尾部。同时通知布局管理器使用指定的 constraints 对象将组件添加到此容器的布局中。这是一个适用于 addImpl(java.awt.Component, java.lang.Object, int) 的便捷方法。
注:如果已经将某个组件添加到显示的容器中,则必须在此容器上调用 validate,以显示新的组件。如果添加多个组件,那么可以在添加所有组件之后,通过只调用一次 validate 来提高效率。
import java.awt.event.*;public class ExaMenu extends Frame implements ActionListener {
CardLayout myCard; Panel cPanel; private Label l1; private Label l2; private TextField text1; private TextField text2; private TextField text3; private Button button1; ExaMenu(String string) {
super(string);
myCard = new CardLayout();
cPanel = new Panel();
cPanel.setLayout(myCard); Panel panel1 = new Panel();
Panel panel2 = new Panel();
Panel panel3 = new Panel(); l1 = new Label("数a");
l2 = new Label("数b");
text1 = new TextField(10);
text2 = new TextField(10);
text3 = new TextField(10);
button1 = new Button("加");
panel1.add(l1);
panel1.add(button1);
panel2.add(text1);
panel3.add(l2); cPanel.add(panel1, "1");
cPanel.add(panel2, "2");
cPanel.add(panel3, "3");
add(cPanel, BorderLayout.CENTER);
setSize(500, 100);
setVisible(true);
button1.addActionListener(this);
} public void actionPerformed(ActionEvent e) {
double n;
if (e.getSource() == button1) {
try {
double n1, n2 = 0;
n1 = Double.parseDouble(text1.getText());
n1 = Double.parseDouble(text1.getText());
n = n1 + n2;
text3.setText(String.valueOf(n));
} catch (NumberFormatException ex) {
System.out.println("请输入数字!");
}
} } {
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
} public static void main(String args[]) {
new ExaMenu("Menu");
}
}