我正在研究计算定积分的程序。我们的想法是将您想要的系数放入JTextField或JFormattedTextField，程序会计算您的答案。 我偶然发现的问题是我可以输入的唯一数字是整数。我正在寻找一种投入双打的方法。 我现在这样做的方式是使用 NumberFormat 和 NumberFormatter ，但我找不到让它接受十进制格式的方法。
这是我的框架代码：
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import javax.swing.JButton;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.text.NumberFormatter;
public class IntegrationFrame extends JFrame {
private static final long serialVersionUID = 1L;
private JFormattedTextField txtLwrBnd;
private JFormattedTextField txtUprBnd;
private JFormattedTextField txtA;
private JFormattedTextField txtB;
private JFormattedTextField txtC;
private JLabel lblLwrBnd;
private JLabel lblUprBnd;
private JLabel lblA;
private JLabel lblB;
private JLabel lblC;
private JTextField txtAnswer;
double uprBnd = 1;
double lwrBnd = 0;
double a = 1;
double b = 1;
double c = 1;
private double tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmpUpr, tmpLwr, result;
private String answer;
//Creating the frame
public IntegrationFrame(int enabled, int fNumber){ //enabled - which const. are on
setResizable(false); /// fNumber - number of integral function
setLocationRelativeTo(null);
this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
this.setSize(335,480);
getContentPane().setLayout(null);
NumberFormat format = NumberFormat.getInstance();
NumberFormatter formatter = new NumberFormatter(format);
formatter.setValueClass(Integer.class);
formatter.setMinimum(0);
formatter.setMaximum(Integer.MAX_VALUE);
formatter.setAllowsInvalid(true);
// If you want the value to be committed on each keystroke instead of focus lost
formatter.setCommitsOnValidEdit(true);
txtLwrBnd = new JFormattedTextField(formatter);
txtLwrBnd.setText("0");
txtLwrBnd.setBounds(46, 118, 56, 22);
getContentPane().add(txtLwrBnd);
txtLwrBnd.setColumns(10);
JLabel lblTitle = new JLabel("Enter coefficients\n");
lblTitle.setHorizontalAlignment(SwingConstants.CENTER);
lblTitle.setBounds(12, 34, 299, 16);
getContentPane().add(lblTitle);
txtUprBnd = new JFormattedTextField(formatter);
txtUprBnd.setText("1");
txtUprBnd.setBounds(227, 118, 56, 22);
getContentPane().add(txtUprBnd);
txtUprBnd.setColumns(10);
txtA = new JFormattedTextField(formatter);
txtA.setText("1");
txtA.setBounds(46, 202, 56, 22);
getContentPane().add(txtA);
txtA.setColumns(10);
txtB = new JFormattedTextField(formatter);
txtB.setText("1");
txtB.setBounds(143, 202, 56, 22);
getContentPane().add(txtB);
txtB.setColumns(10);
txtC = new JFormattedTextField(formatter);
txtC.setText("1");
txtC.setBounds(242, 202, 56, 22);
getContentPane().add(txtC);
txtC.setColumns(10);
lblLwrBnd = new JLabel("Lower Bound");
lblLwrBnd.setHorizontalAlignment(SwingConstants.CENTER);
lblLwrBnd.setBounds(12, 89, 116, 16);
getContentPane().add(lblLwrBnd);
lblUprBnd = new JLabel("Upper Bound");
lblUprBnd.setHorizontalAlignment(SwingConstants.CENTER);
lblUprBnd.setBounds(195, 89, 116, 16);
getContentPane().add(lblUprBnd);
lblA = new JLabel("a =");
lblA.setBounds(12, 205, 30, 16);
getContentPane().add(lblA);
lblB = new JLabel("b =");
lblB.setBounds(114, 205, 30, 16);
getContentPane().add(lblB);
lblC = new JLabel("c =");
lblC.setBounds(213, 205, 30, 16);
getContentPane().add(lblC);
if (enabled == 1) {
txtC.setEnabled(false);
lblC.setEnabled(false);
}
else if (enabled == 2) {
txtB.setEnabled(false);
lblB.setEnabled(false);
txtC.setEnabled(false);
lblC.setEnabled(false);
}
else {
txtB.setEnabled(true);
lblB.setEnabled(true);
txtC.setEnabled(true);
lblC.setEnabled(true);
}
JButton btnCalculate = new JButton("Compute");
btnCalculate.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (fNumber == 1) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
tmpUpr = uprBnd;
tmpLwr = lwrBnd;
result = a*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 2) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/(b+1);
tmpUpr = Math.pow(uprBnd, b+1);
tmpLwr = Math.pow(lwrBnd, b+1);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 3) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
tmp1 = a/2;
tmpUpr = Math.pow(uprBnd, 2);
tmpLwr = Math.pow(lwrBnd, 2);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 4) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
tmp1 = a;
tmpUpr = Math.log(uprBnd);
tmpLwr = Math.log(lwrBnd);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 5) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
c = Double.parseDouble(txtC.getText());
tmp1 = a/(c*Math.log(a));
tmpUpr = Math.pow(b, uprBnd*c);
tmpLwr = Math.pow(b, lwrBnd*c);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 6) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmpUpr = Math.exp(uprBnd*b);
tmpLwr = Math.exp(lwrBnd*b);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 7) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmpUpr = -Math.cos(uprBnd*b);
tmpLwr = -Math.cos(lwrBnd*b);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 8) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmpUpr = Math.sin(uprBnd*b);
tmpLwr = Math.sin(lwrBnd*b);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 9) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmp2 = Math.cos(uprBnd*b);
tmp3 = Math.cos(lwrBnd*b);
tmpUpr = -Math.log(tmp2);
tmpLwr = -Math.log(tmp3);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 10) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmp2 = Math.sin(uprBnd*b);
tmp3 = Math.sin(lwrBnd*b);
tmpUpr = Math.log(tmp2);
tmpLwr = Math.log(tmp3);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 11) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmpUpr = Math.tan(uprBnd*b);
tmpLwr = Math.tan(lwrBnd*b);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 12) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
tmp1 = a/b;
tmp2 = Math.tan(uprBnd*b);
tmp3 = Math.tan(lwrBnd*b);
tmpUpr = -1/tmp2;
tmpLwr = -1/tmp3;
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 13) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
c = Double.parseDouble(txtC.getText());
tmp2 = Math.sqrt(b);
tmp1 = a/(c*tmp2);
tmpUpr = Math.atan(uprBnd*tmp2/c);
tmpLwr = Math.atan(lwrBnd*tmp2/c);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 14) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
c = Double.parseDouble(txtC.getText());
tmp2 = Math.sqrt(b);
tmp1 = a/(2*c*tmp2);
tmp3 = uprBnd*tmp2;
tmp4 = lwrBnd*tmp2;
tmpUpr = Math.log((tmp3-c)/(tmp3+c));
tmpLwr = Math.log((tmp4-c)/(tmp4+c));
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 15) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
c = Double.parseDouble(txtC.getText());
tmp2 = Math.sqrt(c);
tmp1 = a/tmp2;
tmpUpr = Math.asin(uprBnd*tmp2/b);
tmpLwr = Math.asin(lwrBnd*tmp2/b);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else if (fNumber == 16) {
lwrBnd = Double.parseDouble(txtLwrBnd.getText());
uprBnd = Double.parseDouble(txtUprBnd.getText());
a = Double.parseDouble(txtA.getText());
b = Double.parseDouble(txtB.getText());
c = Double.parseDouble(txtC.getText());
tmp2 = Math.sqrt(b);
tmp1 = 1/tmp2;
tmp5 = Math.pow(uprBnd, 2);
tmp6 = Math.pow(lwrBnd, 2);
tmp3 = Math.sqrt(b*tmp5 + c);
tmp4 = Math.sqrt(b*tmp6 + c);
tmpUpr = Math.log(uprBnd + tmp3);
tmpLwr = Math.log(lwrBnd + tmp4);
result = tmp1*(tmpUpr - tmpLwr);
answer = String.format("%.4f", result);
txtAnswer.setText(answer);
}
else {
System.out.println(":C");
}
}
});
btnCalculate.setBounds(114, 293, 97, 25);
getContentPane().add(btnCalculate);
txtAnswer = new JTextField();
txtAnswer.setEditable(false);
txtAnswer.setBounds(107, 375, 116, 22);
getContentPane().add(txtAnswer);
txtAnswer.setColumns(10);
JLabel lblAnswer = new JLabel("Answer\r\n");
lblAnswer.setHorizontalAlignment(SwingConstants.CENTER);
lblAnswer.setBounds(107, 345, 116, 16);
getContentPane().add(lblAnswer);
}
public static void main(String[] args) {
IntegrationFrame frame = new IntegrationFrame(2, 1);
frame.setVisible(true);
}
}