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package calc;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
public class calc1 extends JFrame {
public JButton plus;
public JButton minus;
public JButton multiply;
public JButton divide;
public JTextField num1;
public JTextField num2;
public JTextField res;
public long numb1;
public long numb2;
public long result;
public String boob;
public String boob2;
public calc1(){
setSize(400,400);
setLayout(new FlowLayout());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
這是我想從文本框「NUM1」的值來把它變成一個int /長/雙,所以我能問題在我的聽衆下面的數學函數中使用它。試圖把文本框的值轉換成int /雙,數字格式異常錯誤
num1 = new JTextField("Enter First Number:");
boob = num1.getText();
numb1 = Long.parseLong(boob);
add(num1);
這是我想從文本框「NUM1」的值的問題把它變成一個int /長/雙,所以我可以用它在數學函數在我的聽衆吼叫。
num2 = new JTextField("Enter Second Number:");
boob2 = num2.getText();
numb2 = Long.parseLong(boob2);
add(num2);
plus = new JButton("+");
add(plus);
minus = new JButton("-");
add(minus);
multiply = new JButton("*");
add(multiply);
divide = new JButton(":");
add(divide);
listener1 boo1 = new listener1();
listener2 boo2 = new listener2();
listener3 boo3 = new listener3();
listener4 boo4 = new listener4();
divide.addActionListener(boo1);
multiply.addActionListener(boo2);
minus.addActionListener(boo3);
plus.addActionListener(boo4);
}
public class listener1 implements ActionListener{
public void actionPerformed(ActionEvent boo1){
result = numb1/numb2;
String ahmood = String.valueOf(result);
res = new JTextField(ahmood);
add(res);
}
}
public class listener2 implements ActionListener{
public void actionPerformed(ActionEvent boo2){
result = numb1*numb2;
String ahmood = String.valueOf(result);
res = new JTextField(ahmood);
add(res);
}
}
public class listener3 implements ActionListener{
public void actionPerformed(ActionEvent boo3){
result = numb1-numb2;
String ahmood = String.valueOf(result);
res = new JTextField(ahmood);
add(res);
}
}
public class listener4 implements ActionListener{
public void actionPerformed(ActionEvent boo4){
result = numb1+numb2;
String ahmood = String.valueOf(result);
res = new JTextField(ahmood);
add(res);
}
}
public static void main(String args[]){
calc1 joss = new calc1();
joss.setVisible(true);
}
}
我試過很多方法,我結束了與許多冗餘變量。這是我不斷收到的錯誤。
Exception in thread "main" java.lang.NumberFormatException: For input string: "Enter First Number:"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Long.parseLong(Long.java:589)
at java.lang.Long.parseLong(Long.java:631)
at calc.calc1.<init>(calc1.java:37)
at calc.calc1.main(calc1.java:135)
我正在建造一個新的,謝謝 –