这是我为一个小型gui编写的完整代码，它可以从用户那里获取变量，并将它们返回到程序的其他部分（r.o.p）进行计算，但似乎没有传递到r.o.p，也没有观察到输出文件。
任何帮助都将不胜感激，我认为问题在于Draw New Graph命令的侦听器。感谢
代码：
import java.text.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class RungeKutta {
// class to create slider and window
private static File file1;
public static double A(double v, double x, double wc, double beta) {
return (-2 * beta * v - (Math.pow(wc, 2)) * Math.sin(x));
}
public static File getFile1() {
return file1;
}
public static void setFile1(File file1) {
RungeKutta.file1 = file1;
}
public static void main(String[] argv) throws IOException, ParseException {
createAndShowGUI();
}
private static void createAndShowGUI() {
//create and set up the window.
JFrame frame = new JFrame("RungeKutta");
GridLayout first = new GridLayout(14,1);
frame.setLayout(first);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create, name and Populate TextField
JTextField PL = new JTextField("Pendulum Length", 20);
//Set TextField to Uneditable. Each will have Empty Field Below For Variables
PL.setEditable(false);
//Set Textfield for user entered dat
JTextField PLv = new JTextField();
//Allow input from text field to be taken
JTextField AD = new JTextField("Angular Displacement", 20);
AD.setEditable(false);
JTextField ADv = new JTextField();
JTextField AV = new JTextField("Angular Velocity", 20);
AV.setEditable(false);
JTextField Avv = new JTextField();
JTextField TS= new JTextField("Time Steps", 20);
TS.setEditable(false);
JTextField TSv = new JTextField();
JTextField MT = new JTextField("Max Time", 20);
MT.setEditable(false);
JTextField MTv = new JTextField();
JTextField V = new JTextField("Viscosity (0-1)", 20);
V.setEditable(false);
JTextField Vv = new JTextField();
//Create Button to Restart and Button to take in Values for usage
JLabel emptyLabel = new JLabel("");
emptyLabel.setPreferredSize(new Dimension(600,500));
frame.getContentPane().add(PL, first);
frame.getContentPane().add(PLv, first);
frame.getContentPane().add(AD, first);
frame.getContentPane().add(ADv, first);
frame.getContentPane().add(AV, first);
frame.getContentPane().add(Avv, first);
frame.getContentPane().add(TS, first);
frame.getContentPane().add(TSv, first);
frame.getContentPane().add(MT, first);
frame.getContentPane().add(MTv, first);
frame.getContentPane().add(V, first);
frame.getContentPane().add(Vv, first);
JButton BNewGraph = new JButton("Draw New Graph"); //Button to restart entire drawing process
frame.getContentPane().add(BNewGraph, first);
//display the window
frame.pack();
frame.setVisible(true);
class intakegui implements ActionListener
{
public intakegui()
{
BNewGraph.addActionListener((ActionListener) this);
BNewGraph.setActionCommand("Click to Draw");
}
@Override
public void actionPerformed(ActionEvent e) {
double l = Double.parseDouble(PLv.getText());
double xi = Double.parseDouble(ADv.getText());
double vi = Double.parseDouble(Avv.getText());
double dt = Double.parseDouble(TSv.getText());
double n = Double.parseDouble(MTv.getText());
double beta = Double.parseDouble(Vv.getText());
SimpleDateFormat dform = new SimpleDateFormat("ddMMyyyysmH");
Date d = Calendar.getInstance().getTime();
String dstr = dform.format(d);
String filename = ("result " + dstr + ".txt");
file1 = new File(filename);
PrintWriter savedValues = null;
try {
savedValues = new PrintWriter(filename);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
//declare variable for gravity and omega*c
double g = 9.8;
double wc = Math.sqrt(g / l);
savedValues.println("#Initial Values Entered");
savedValues.println("#" + l + "," + vi + "," + xi + "," + dt + "," + n
+ "," + beta);
double[] dispTime = new double[(int) n];
double[] velTime = new double[(int) n];
// let a = angular acceleration
for (double j = 0; j < (int) n; j++) {
// int time = 1;
double k1v = dt * j * A(vi, xi, wc, beta);
double k1x = dt * j * vi;
double k2v = dt * j * A(vi, xi + (0.5 * k1x), wc, beta);
double k2x = dt * j * (vi + (0.5 * k1v));
double k3v = dt * j * A(vi, xi + (0.5 * k2x), wc, beta);
double k3x = dt * j * (vi + (0.5 * k2v));
double k4v = dt * j * A(vi, xi + k3x, wc, beta);
double k4x = dt * j * (vi + k3v);
xi += k1x / 6 + k2x / 3 + k3x / 3 + k4x / 6;
vi += k1v / 6 + k2v / 3 + k3v / 3 + k4v / 6;
dispTime[(int) j] = xi;
velTime[(int) j] = vi;
System.out.println(xi + "," + vi);
}
for (int i = 0; i < (int) n; i++) {
savedValues.println(dispTime[i] + " " + velTime[i]);
}
savedValues.close();
System.out.println("File saved. File name: " + filename);
}
}
}
}
您忘记将监听器添加到按钮中。您需要添加如下侦听器：
BNewGraph.addActionListener(new intakegui());
现在，当用户单击按钮时，您将看到该文件。