我是一个java初学者,想用japplet做一个小计算器,这是其中 “+”法运算的程序 怎么运行不了啊 哪位高手帮看一下 谢了~~import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class MyComputer extends JApplet implements ActionListener{
JLabel num1Label,num2Label,resultLabel;
JTextField num1Field,num2Field,resultField;
JButton jiaButton;
String num1Val = num1Field.getText();
String num2Val = num2Field.getText(); int num1 = Integer.parseInt(num1Val);
int num2 = Integer.parseInt(num2Val);
public void init()
{
Container container = getContentPane();
container.setLayout(new FlowLayout());
//定义num1
num1Label = new JLabel( "num1");
container.add(num1Label);
num1Field = new JTextField( 10 );
container.add( num1Field );
//定义num2
num2Label = new JLabel( "num2");
container.add(num2Label);
num2Field = new JTextField( 10 );
container.add( num2Field );
//定义result
resultLabel = new JLabel( "result ");
container.add( resultLabel);
container.add( resultLabel );
resultField = new JTextField( 10 );
resultField.setEditable( false );
container.add( resultField );
//定义+
jiaButton = new JButton( "+" );
jiaButton.addActionListener( this );
container.add( jiaButton );
}
public void actionPerformed( ActionEvent actionevent )
{
int sum1;
sum1 = num1 + num2;
resultField.setText( "sum1 = " + sum1 );
}
}
import javax.swing.*;
import java.awt.event.*;
public class MyComputer extends JApplet implements ActionListener{
JLabel num1Label,num2Label,resultLabel;
JTextField num1Field,num2Field,resultField;
JButton jiaButton;
String num1Val = num1Field.getText();
String num2Val = num2Field.getText(); int num1 = Integer.parseInt(num1Val);
int num2 = Integer.parseInt(num2Val);
public void init()
{
Container container = getContentPane();
container.setLayout(new FlowLayout());
//定义num1
num1Label = new JLabel( "num1");
container.add(num1Label);
num1Field = new JTextField( 10 );
container.add( num1Field );
//定义num2
num2Label = new JLabel( "num2");
container.add(num2Label);
num2Field = new JTextField( 10 );
container.add( num2Field );
//定义result
resultLabel = new JLabel( "result ");
container.add( resultLabel);
container.add( resultLabel );
resultField = new JTextField( 10 );
resultField.setEditable( false );
container.add( resultField );
//定义+
jiaButton = new JButton( "+" );
jiaButton.addActionListener( this );
container.add( jiaButton );
}
public void actionPerformed( ActionEvent actionevent )
{
int sum1;
sum1 = num1 + num2;
resultField.setText( "sum1 = " + sum1 );
}
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;public class MyComputer extends JApplet implements ActionListener {
JLabel num1Label, num2Label, resultLabel;
JTextField num1Field, num2Field, resultField;
JButton jiaButton;
String num1Val;
String num2Val; int num1;
int num2; public void init() {
Container container = getContentPane();
container.setLayout(new FlowLayout());
num1Label = new JLabel("num1");
container.add(num1Label);
num1Field = new JTextField(10);
container.add(num1Field);
num2Label = new JLabel("num2");
container.add(num2Label);
num2Field = new JTextField(10);
container.add(num2Field);
resultLabel = new JLabel("result ");
container.add(resultLabel);
container.add(resultLabel);
resultField = new JTextField(10);
resultField.setEditable(false);
container.add(resultField);
jiaButton = new JButton("+");
jiaButton.addActionListener(this);
container.add(jiaButton); } public void actionPerformed(ActionEvent actionevent) {
int sum1;
num1Val = num1Field.getText().trim().toString();
num2Val = num2Field.getText().trim().toString();
num1 = Integer.parseInt(num1Val);
num2 = Integer.parseInt(num2Val);
sum1 = num1 + num2; resultField.setText("sum1 = " + sum1); }}
num1Val = num1Field.getText().trim().toString();
num2Val = num2Field.getText().trim().toString();
这两句是什么意思啊
世纪这里没有必要调用toString()了.
toString() 因為打習慣了~~~~~ 每次總習慣性的打出來·~
那个这一部分
num1Val = num1Field.getText().trim().toString();
num2Val = num2Field.getText().trim().toString();
num1 = Integer.parseInt(num1Val);
num2 = Integer.parseInt(num2Val);
放在前面为什么不行啊