我是 Java 新手，必须创建一个 BMI 计算器，允许用户输入公制或英制测量值，并使用计算 BMI 的方程之一来计算 BMI。我已经使用了公制计算，并且公制测量结果显示正确。我现在需要将英制测量值转换为公制，然后使用现有的公制 BMI 计算，显示答案。如果有人能提供帮助，我将不胜感激。
这是我到目前为止所拥有的:
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.SwingConstants;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JOptionPane;
import java.awt.Font;
public class BMIFrame extends JFrame{
// Create instructions label
private JLabel instructions = new JLabel("<html>To calculate your Body
Mass Index (BMI), please "
+ "enter your weight and height in the fields provided in either
Imperial or Metric measurements.</html>");
// Metric section labels and fields
private JLabel metricHeading = new JLabel("Metric");
private JLabel metricWeight = new JLabel("Enter your Weight:");
private JTextField metTextWeight = new JTextField("0");
private JLabel weightKg = new JLabel("kgs");
private JLabel metricHeight = new JLabel("Enter your Height:");
private JTextField metTextHeight = new JTextField("0");
private JLabel heightCm = new JLabel("cms");
// Imperial section labels and fields
private JLabel imperialHeading = new JLabel("Imperial");
private JLabel imperialWeight = new JLabel("Enter your Weight:");
private JTextField impTextWeight = new JTextField("0");
private JLabel weightSt = new JLabel("st");
private JTextField impTextWeight2 = new JTextField("0");
private JLabel weightLbs = new JLabel("lbs");
private JLabel imperialHeight = new JLabel("Enter your Height:");
private JTextField impTextHeight = new JTextField("0");
private JLabel heightFt = new JLabel("ft");
private JTextField impTextHeight2= new JTextField("0");
private JLabel heightIns = new JLabel("ins");
private JButton calculateButton = new JButton("Calculate BMI");
private JButton clearButton = new JButton("Clear");
private JButton quitButton = new JButton("Quit");
private JLabel bmiInfoHeading = new JLabel("BMI Values");
private JLabel bmiInfoUnder = new JLabel("Below 18.5 = Underweight");
private JLabel bmiInfoNormal = new JLabel("18.5 - 24.9 = Normal");
private JLabel bmiInfoOver = new JLabel("25.0 - 29.9 = Overweight");
private JLabel bmiInfoObese = new JLabel("30.0 + = Obese");
// create a this is your result label
private JLabel bmiResult = new JLabel("Your BMI is ");
private JTextField resultField = new JTextField("0");
public BMIFrame() {
setLayout(null);
// Add instructions
instructions.setBounds(5, 5, 475, 38);
instructions.setBackground(getBackground());
instructions.setFont(new Font("Arial", Font.PLAIN, 13));
add(instructions);
// Add Metric heading
metricHeading.setBounds(90, -25, 225, 200);
metricHeading.setFont(new Font("Arial", Font.BOLD, 14));
add(metricHeading);
// Add Metric Weight Label
metricWeight.setBounds(5, 5, 225, 200);
metricWeight.setFont(new Font("Arial", Font.PLAIN, 13));
add(metricWeight);
// Add Metric Weight input field
metTextWeight.setBounds(120, 92, 50, 25);
metTextWeight.setHorizontalAlignment(SwingConstants.RIGHT);
add(metTextWeight);
// Add Kilogram label to weight field
weightKg.setBounds(172, 5, 225, 200);
weightKg.setFont(new Font("Arial", Font.PLAIN, 13));
add(weightKg);
// Add Metric Height Label
metricHeight.setBounds(5, 40, 225, 200);
metricHeight.setFont(new Font("Arial", Font.PLAIN, 13));
add(metricHeight);
// Add Metric Height input field
metTextHeight.setBounds(120, 127, 50, 25);
metTextHeight.setHorizontalAlignment(SwingConstants.RIGHT);
add(metTextHeight);
// Add Centimetres label to weight field
heightCm.setBounds(172, 40, 225, 200);
heightCm.setFont(new Font("Arial", Font.PLAIN, 13));
add(heightCm);
// Add imperial measurements fields
imperialHeading.setBounds(330, -25, 225, 200);
imperialHeading.setFont(new Font("Arial", Font.BOLD, 14));
add(imperialHeading);
// Add Imperial Weight Label
imperialWeight.setBounds(225, 5, 225, 200);
imperialWeight.setFont(new Font("Arial", Font.PLAIN, 13));
add(imperialWeight);
// Add Imperial Weight input field
impTextWeight.setBounds(335, 92, 50, 25);
impTextWeight.setHorizontalAlignment(SwingConstants.RIGHT);
add(impTextWeight);
// Add Stone label to weight field
weightSt.setBounds(385, 5, 225, 200);
weightSt.setFont(new Font("Arial", Font.PLAIN, 13));
add(weightSt);
// Add second Imperial Weight input field
impTextWeight2.setBounds(400, 92, 50, 25);
impTextWeight2.setHorizontalAlignment(SwingConstants.RIGHT);
add(impTextWeight2);
// Add Pounds label to weight field
weightLbs.setBounds(451, 5, 225, 200);
weightLbs.setFont(new Font("Arial", Font.PLAIN, 13));
add(weightLbs);
// Add Imperial Height Label
imperialHeight.setBounds(225, 40, 225, 200);
imperialHeight.setFont(new Font("Arial", Font.PLAIN, 13));
add(imperialHeight);
// Add Imperial Height input field
impTextHeight.setBounds(335, 127, 50, 25);
impTextHeight.setHorizontalAlignment(SwingConstants.RIGHT);
add(impTextHeight);
// Add Feet label to weight field
heightFt.setBounds(386, 40, 225, 200);
heightFt.setFont(new Font("Arial", Font.PLAIN, 13));
add(heightFt);
// Add Imperial Height input field
impTextHeight2.setBounds(400, 127, 50, 25);
impTextHeight2.setHorizontalAlignment(SwingConstants.RIGHT);
add(impTextHeight2);
// Add Inches label to height field
heightIns.setBounds(451, 40, 225, 200);
heightIns.setFont(new Font("Arial", Font.PLAIN, 13));
add(heightIns);
// Add Calculate button
calculateButton.setBounds(175, 175, 125, 50);
add(calculateButton);
// Add Clear button
clearButton.setBounds(120, 360, 115, 30);
add(clearButton);
// Add Quit button
quitButton.setBounds(240, 360, 115, 30);
add(quitButton);
// Result label
bmiResult.setBounds(10, 240, 80, 50);
add(bmiResult);
// Add result field
resultField.setBounds(86, 243, 80, 40);
resultField.setHorizontalAlignment(SwingConstants.CENTER);
resultField.setEditable(false);
add(resultField);
// BMI values display
bmiInfoHeading.setBounds(345, 230, 80, 50);
add(bmiInfoHeading);
bmiInfoUnder.setBounds(300, 255, 200, 50);
bmiInfoUnder.setFont(new Font("Arial", Font.PLAIN, 13));
add(bmiInfoUnder);
bmiInfoNormal.setBounds(300, 275, 200, 50);
bmiInfoNormal.setFont(new Font("Arial", Font.PLAIN, 13));
add(bmiInfoNormal);
bmiInfoOver.setBounds(300, 295, 200, 50);
bmiInfoOver.setFont(new Font("Arial", Font.PLAIN, 13));
add(bmiInfoOver);
bmiInfoObese.setBounds(300, 315, 200, 50);
bmiInfoObese.setFont(new Font("Arial", Font.PLAIN, 13));
add(bmiInfoObese);
ButtonHandler bh = new ButtonHandler();
calculateButton.addActionListener(bh);
clearButton.addActionListener(bh);
quitButton.addActionListener(bh);
} // end of constructor
// private inner class ButtonHandler
private class ButtonHandler implements ActionListener{
public void actionPerformed(ActionEvent event) {
if (event.getSource() == quitButton)
System.exit(0);
else if (event.getSource() == clearButton) {
metTextWeight.setText("0");
metTextHeight.setText("0");
impTextWeight.setText("0");
impTextWeight2.setText("0");
impTextHeight.setText("0");
impTextHeight2.setText("0");
resultField.setText("0");
return;
}
try {
double metW1 = Double.parseDouble(metTextWeight.getText());
double metH1 = Double.parseDouble(metTextHeight.getText());
double impW1 = Double.parseDouble(impTextWeight.getText());
double impW2 = Double.parseDouble(impTextWeight2.getText());
double impH1 = Double.parseDouble(impTextHeight.getText());
double impH2 = Double.parseDouble(impTextHeight2.getText());
double result = 0;
if (event.getSource() == calculateButton)
result = (metW1 / (metH1 * metH1) * 10000);
String answers = String.format("%.1f", result);
resultField.setText(answers);
} // end of try method
catch(Exception ex) {
JOptionPane.showMessageDialog(BMIFrame.this, ex.toString()
, "Error Message", JOptionPane.WARNING_MESSAGE);
} // end of catch method
} // end of method actionPerformed
} // end of inner class ButtonHandler
} //end of class BMIFrame
最佳答案
我建议采用不同的方法，这应该有助于简化代码。考虑这个接口(interface):
public interface BMICalculator {
public double calculate(double height, double weight);
}
还有两个实现:
public class MetricBMICalculator implements BMICalculator {
public double calculate(double heightCentimeters, double weightKilograms) {
// convert as needed, calculate, and return...
}
}
public class ImperialBMICalculator implements BMICalculator {
public double calculate(double heightFeet, double weightPounds) {
// convert as needed, calculate, and return...
}
}
用户界面内有一个单位切换开关，可以在公制和英制之间切换。这导致只需要一个体重输入字段和一个高度输入字段。当触发切换时，相关标签的文本会发生变化，并且上述接口(interface)的实现也会发生变化。
关于java - 使用公制方程计算 BMI，如何在 Java 中使用 GUI 转换英制测量值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47557088/