问题描述
我将构建一个简单的 Swing UI 应用程序,从单独的 JTextField 获取用户的输入,然后最后单击一个 Button 以执行添加以在 JButton 下方的 JTextField 上显示。
输入字段(JTextField)用于接收整数值。
package com.APPOne_G5;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class AppOne_G5 {
private JPanel calculatorFrame;
private JTextField inputField1;
private JTextField inputField2;
private JButton calculateButton;
private JTextField outputField;
private JLabel inputFieldLabel1;
private JLabel inputFieldLabel2;
private JLabel outputFieldLabel;
private int number1,number2;
private int calc = number1 + number2;
public AppOne_G5() {
inputField1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
number1 = Integer.parseInt(inputField1.getText());
}
});
inputField2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
number2 = Integer.parseInt(inputField2.getText());
}
});
calculateButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
calc = number1 + number2;
outputField.setText(String.valueOf(number1+number2));
}
});
outputField.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
outputField.setEditable(false);
outputField.setText(String.valueOf(calc));
}
});
}
public static void main(String[] args) {
JFrame app = new JFrame("Group 5 AppOne");
app.setDefaultCloSEOperation(app.EXIT_ON_CLOSE);
app.setContentPane(new AppOne_G5().calculatorFrame);
app.setLocationRelativeto(null);
app.setVisible(true);
app.pack();
}
}
我输入要添加的值后得到零。
This is the GUI form of the application
解决方法
根据我的评论,您只需要一个单击按钮时激活的动作侦听器。这是一个完整的工作示例,说明它如何工作:
public class AppOne_G5 {
private JFrame app = new JFrame("Group 5 AppOne");
private JPanel calculatorFrame = new JPanel();
private JTextField inputField1 = new JTextField("2");
private JTextField inputField2 = new JTextField("5");
private JButton calculateButton = new JButton("Calculate");
private JTextField outputField = new JTextField(" ");
private JLabel inputFieldLabel1 = new JLabel("Enter Integer");
private JLabel inputFieldLabel2 = new JLabel("Enter Integer");;
private JLabel outputFieldLabel = new JLabel("Result");
private int number1,number2;
private int calc;
public AppOne_G5() {
//Add components in order
app.add(calculatorFrame);
app.setDefaultCloseOperation(app.EXIT_ON_CLOSE);
calculatorFrame.add(inputFieldLabel1);
calculatorFrame.add(inputField1);
calculatorFrame.add(inputFieldLabel2);
calculatorFrame.add(inputField2);
calculatorFrame.add(calculateButton);
calculatorFrame.add(outputFieldLabel);
calculatorFrame.add(outputField);
//Create action listener
calculateButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//Get the inputs
number1 = Integer.parseInt(inputField1.getText());
number2 = Integer.parseInt(inputField2.getText());
System.out.println("number 1: " + number1 + ",number2: " + number2);
//Calculate the output
calc = number1 + number2;
System.out.println("number 1: " + number1 + ",number2: " + number2 + ",calc: "+calc);
//Show the output
outputField.setText(String.valueOf(calc));
}
});
//Show JFrame
app.setVisible(true);
app.pack();
}
public static void main(String[] args) {
new AppOne_G5();
}
}
要调试未获得预期输出的原因,您可以使用 System.out.println("...");
。例如,如果您要使用以下内容,那么您可以查看问题是否是因为 calc 错误,或者 numebr1 或 number2 是否已经为零:
calc = number1 + number2;
System.out.println("number 1: " + number1 + ",calc: "+calc);
一旦您知道问题出在哪里,您就可以进一步返回代码并找出该值为零的原因。
,正如 Scorfield 提到的,您只需要 calculateButton
上的一个 ActionListener。这就是您应该获取用户输入的文本的地方。