java - JApplet 程序 : error: ')' expected, 错误 : illegal start of type, 预期，错误: ';' 预期

Question

代码:

import java.awt.*; 

import javax.swing.*; 

import java.awt.event.*; 

public class DoubleIt extends JApplet implements actionListener { 

         JLable lValue; 

         JTextField tValue; 

         JButton bDoubble; 

 public void init(){ 
        setSize(200,400);
        Container panel;
        panel = getContent.Pane(); 
        panel.setLayout( new FlowLayout());
        lValue = new JLable("Int Value"); 
        tValue = new Jtextfield(15);
        tValue.SetText("125"); 
        panel.add(lValue); 
        panel.add(tValue); 
        bDoubble = new JButton("*"); 
        panel.add(bDoubble); 
        bDoubble.add.ActionListiner(this); 
        }//end init 

 public void actionPerformed(ActionEvent event); 
        int value; 
        value = Integer.parseInt(tValue.getText()); 
        value = value * 2; 
        tValue.setText(" "+value); 
        }//end method 
     }//end main 

错误:

DoubleIt.java:27:错误:需要标识符

        value = Integer.parseInt(tValue.getText()); 
             ^

DoubleIt.java:28:错误:需要标识符

        value = value * 2; 
             ^

DoubleIt.java:29:错误:需要标识符

        tValue.setText(" "+value); 
                      ^

DoubleIt.java:29: 错误:类型非法开始

       tValue.setText(" "+value); 
                       ^

DoubleIt.java:29: 错误:预期为“)”

        tValue.setText(" "+value); 
                          ^

DoubleIt.java:29: 错误: ';'预计

        tValue.setText(" "+value); 
                           ^

DoubleIt.java:29: 错误:类型非法开始

        tValue.setText(" "+value); 
                                ^

DoubleIt.java:29:错误:需要标识符

              tValue.setText(" "+value); 
                                 ^

DoubleIt.java:29: 错误: ';'预计

        tValue.setText(" "+value); 
                                  ^ 

我的问题:

我有编译器说我缺少的所有东西，这是括号问题吗？

Answer 1

你的问题就在这里......

public void actionPerformed(ActionEvent event); <--- See the semi colen...

应该是..

public void actionPerformed(ActionEvent event) {

还有...

JLable lValue;
//...
lValue = new JLable("Int Value");

应该是...

JLabel lValue;
//...
lValue = new JLabel("Int Value");

还有...

tValue = new Jtextfield(15);

应该是...

tValue = new JTextField(15);

还有...

tValue.SetText("125");

应该是...

tValue.setText("125");

还有...

bDoubble.add.ActionListiner(this);

应该是...

bDoubble.addActionListener(this);

还有...

public class DoubleIt extends JApplet implements actionListener

应该是...

public class DoubleIt extends JApplet implements ActionListener

还有...

panel = getContent.Pane();

应该是...

panel = getContentPane();

记住，Java 区分大小写，大小写很重要