我目前正在使用JSwing开发一个程序。
我让程序使用正确的逻辑，但出于某种原因，当我输入第一个输入时，它会创建一个具有正确更改的新窗口。
它只创建一个新窗口。
以下是我的转换器的代码
public class Converter extends JFrame{
//Creating text fields to be put into the "Distance" Tab
JTextField metersTxt = new JTextField(), feetTxt = new JTextField(),milesTxt = new JTextField(),
inchesTxt = new JTextField(), cmTxt = new JTextField(), kmTxt = new JTextField();
public Converter(){
//Creating the GUI object for frame
JFrame frame = new JFrame("Distance/Energy Converter");
frame.setSize(600, 600);
frame.setVisible(true);
//Assigning a name to JTextFile
metersTxt.setName("meters");
feetTxt.setName("feet");
milesTxt.setName("miles");
inchesTxt.setName("inches");
cmTxt.setName("cm");
kmTxt.setName("km");
//Making an instance of a tabbedPane to be able to add 2 panes.
JTabbedPane tabbedPane = new JTabbedPane();
//Making the first tab to convert distance values
JPanel panel1 = new JPanel(true);
tabbedPane.addTab("Distance", panel1);
panel1.setLayout(new GridLayout(0,6));
//A second tab to switch to energy conversions
JPanel panel2 = new JPanel(true);
tabbedPane.addTab("Energy", panel2);
panel2.setLayout(new GridLayout(0,6));
//Add the tabbedPane to this panel.
frame.add(tabbedPane);
//Creates labels for the "Distance" tab
JLabel meters = new JLabel("Meters");
JLabel feet = new JLabel("Feet");
JLabel miles = new JLabel("Miles");
JLabel inches = new JLabel("Inches");
JLabel cm = new JLabel("Centimeters");
JLabel km = new JLabel ("Kilometers");
//Create labels for the "Energy" tab
JLabel joule = new JLabel("Joule");
JLabel cal = new JLabel("Calorie");
JLabel volt = new JLabel("Volt");
JLabel watt = new JLabel("Watt");
JLabel thermal = new JLabel("Thermal Units");
//Adding labels and text boxes to distance panel in order to be formatted right
panel1.add(meters);
panel1.add(metersTxt);
panel1.add(feet);
panel1.add(feetTxt);
panel1.add(miles);
panel1.add(milesTxt);
panel1.add(inches);
panel1.add(inchesTxt);
panel1.add(cm);
panel1.add(cmTxt);
panel1.add(km);
panel1.add(kmTxt);
//Allowing the user to edit the text boxes
metersTxt.setEditable(true);
feetTxt.setEditable(true);
milesTxt.setEditable(true);
inchesTxt.setEditable(true);
cmTxt.setEditable(true);
kmTxt.setEditable(true);
//Attaching the metric listener to each JTextField
metersTxt.addActionListener(new MetricListener());
feetTxt.addActionListener(new MetricListener());
milesTxt.addActionListener(new MetricListener());
inchesTxt.addActionListener(new MetricListener());
cmTxt.addActionListener(new MetricListener());
kmTxt.addActionListener(new MetricListener());
//To clean up interface and close it when close the window
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String args[]){
Converter mf = new Converter();
}
}
然后是我的听众课
public class MetricListener implements ActionListener
{
@Override
public void actionPerformed(ActionEvent e)
{
Converter c = null;
c = new Converter();
//Getting where the action takes place
JTextField txt = new JTextField();
txt = (JTextField) e.getSource();
//Extracting input from GUI
String input = null;
input = e.getActionCommand();
//Turing the taken in value into type double
double value = 0;
value = Double.parseDouble(input);
//Variables to hold values for conversions
double meters = 0, feet = 0, miles = 0, inches = 0, cm = 0, km = 0;
String txtName = null;
txtName = txt.getName();
//The following if statements are seeing which JTextField is being changed
if(txtName.equals("meters")){
//Creating conversions from meters
meters = value;
feet = value * .3048;
miles = value * 0.000621371;
inches = value * 39.3701;
cm = value * 100;
km = value * .001;
//Applying the converted values to respected places
c.metersTxt.setText(Double.toString(meters));
c.feetTxt.setText(Double.toString(feet));
c.milesTxt.setText(Double.toString(miles));
c.inchesTxt.setText(Double.toString(inches));
c.cmTxt.setText(Double.toString(cm));
c.kmTxt.setText(Double.toString(km));
}
else if(txtName.equals("feet")){
//Creating conversions from feet
meters = value * .3048;
feet = value ;
miles = value * 0.000189394;
inches = value * 12;
cm = value * 30.48;
km = value * 0.0003048;
//Applying the converted values to respected places
c.metersTxt.setText(Double.toString(meters));
c.feetTxt.setText(Double.toString(feet));
c.milesTxt.setText(Double.toString(miles));
c.inchesTxt.setText(Double.toString(inches));
c.cmTxt.setText(Double.toString(cm));
c.kmTxt.setText(Double.toString(km));
}
else if(txtName.equals("miles")){
//Creating conversions from feet
meters = value * 1609.34;
feet = value * 5280;
miles = value;
inches = value * 63360;
cm = value * 160934;
km = value * 1.60934;
//Applying the converted values to respected places
c.metersTxt.setText(Double.toString(meters));
c.feetTxt.setText(Double.toString(feet));
c.milesTxt.setText(Double.toString(miles));
c.inchesTxt.setText(Double.toString(inches));
c.cmTxt.setText(Double.toString(cm));
c.kmTxt.setText(Double.toString(km));
}
else if(txtName.equals("inches")){
//Creating conversions from feet
meters = value * 0.0254;
feet = value * 0.0833333;
miles = value * .0000157828;
inches = value;
cm = value * 2.54;
km = value * .0000254;
//Applying the converted values to respected places
c.metersTxt.setText(Double.toString(meters));
c.feetTxt.setText(Double.toString(feet));
c.milesTxt.setText(Double.toString(miles));
c.inchesTxt.setText(Double.toString(inches));
c.cmTxt.setText(Double.toString(cm));
c.kmTxt.setText(Double.toString(km));
}
else if(txtName.equals("cm")){
//Creating conversions from feet
meters = value * 0.01;
feet = value * 0.0328084;
miles = value * .00000621371;
inches = value * 0.393701;
cm = value;
km = value * .00001;
//Applying the converted values to respected places
c.metersTxt.setText(Double.toString(meters));
c.feetTxt.setText(Double.toString(feet));
c.milesTxt.setText(Double.toString(miles));
c.inchesTxt.setText(Double.toString(inches));
c.cmTxt.setText(Double.toString(cm));
c.kmTxt.setText(Double.toString(km));
}
else if(txtName.equals("km")){
//Creating conversions from feet
meters = value * 1000f;
feet = value * 3280.84;
miles = value * 0.621371;
inches = value * 39370.1;
cm = value * 100000;
km = value;
//Applying the converted values to respected places
c.metersTxt.setText(Double.toString(meters));
c.feetTxt.setText(Double.toString(feet));
c.milesTxt.setText(Double.toString(miles));
c.inchesTxt.setText(Double.toString(inches));
c.cmTxt.setText(Double.toString(cm));
c.kmTxt.setText(Double.toString(km));
}
}
}
任何帮助将不胜感激！谢谢！
答案 0 :(得分：1)
你的第一个问题是在Converter（）中创建一个新的JFrame。 Converter已经是一个JFrame，所以你可以使用“this”代替auf“frame”。
我认为打开一个新窗口并不打算，所以不要在actionPerformed中创建一个新的Converter。因此，请将转换器的引用提供给MetricListener。如果你让MetricListener成为Converter的内部类，那么它就更容易了。
我试着在这里展示重点：
public class Converter extends JFrame{
//Creating text fields to be put into the "Distance" Tab
JTextField metersTxt = new JTextField(), feetTxt = new JTextField(),milesTxt = new JTextField(), inchesTxt = new JTextField(), cmTxt = new JTextField(), kmTxt = new JTextField();
//Creating the GUI object for frame
public Converter() {
this.setTitle("Distance/Energy Converter");
this.setSize(600, 600);
this.setVisible(true);
...
//Add the tabbedPane to this panel.
this.add(tabbedPane);
...
//To clean up interface and close it when close the window
this.pack();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public class MetricListener implements ActionListener
{
@Override
public void actionPerformed(ActionEvent e)
{
/* DO NOT CREATE A NEW Converter */
...
//The following if statements are seeing which JTextField is being changed
if(txtName.equals("meters")){
....
/* Since it is an inner class you can use these variables directly */
//Applying the converted values to respected places
metersTxt.setText(Double.toString(meters));
feetTxt.setText(Double.toString(feet));
milesTxt.setText(Double.toString(miles));
inchesTxt.setText(Double.toString(inches));
cmTxt.setText(Double.toString(cm));
kmTxt.setText(Double.toString(km));
}
else if(txtName.equals("feet")){
/* and so on */
}
}
}
public static void main(String args[]){
Converter mf = new Converter();
}
}
答案 1 :(得分：1)
您的程序每次都会创建一个新的框架，因为在actionPerformed的{{1}}方法中，您每次都会调用
MetricListener每次都会创建并显示新的c = new Converter();
。
解决方案是每次都避免新转换器的实例化，并将其作为本地字段，例如如下所示
MetricListener
JFrame转换器
public class MetricListener implements ActionListener
{
//add field c of class Converter
private Converter c;
//create COntructor with Converter parameter
public MetricListener(Converter c){
this.c=c;
}
@Override
public void actionPerformed(ActionEvent e)
{
//Comment converte creation
//Converter c = null;
//c = new Converter();
.....
//All the rest of the Class as before