我遇到了这个java代码的问题。我无法启动按钮，当我调整按钮时，它无法识别我的变量（Test1，Test2等）。我已经花了好几个小时在这上面，无论我做出什么改变，我似乎无法做到这一点。有任何想法吗？
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//Main class
public class gui12{
//Declare variables
public static void main (String args[]){
JFrame frame1;
Container pane;
JButton btnCalculate;
JLabel lblTest1,lblWeight1, lblWeight2, lblWeight3, lblWeight4, lblTest2, lblTest3, lblTest4;
JTextField txtTest1, txtTest2, txtTest3, txtTest4, txtWeight1, txtWeight2, txtWeight3, txtWeight4;
Insets insets;
double Average;
//Set Look and Feel
try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());}
catch (ClassNotFoundException e) {}
catch (InstantiationException e) {}
catch (IllegalAccessException e) {}
catch (UnsupportedLookAndFeelException e) {}
//Create the frame
frame1 = new JFrame ("Sample GUI Application");
frame1.setSize (800,200);
pane = frame1.getContentPane();
insets = pane.getInsets();
pane.setLayout (null);
//Create controls
btnCalculate = new JButton ("Calculate");
lblTest1 = new JLabel ("Test1:");
lblTest2 = new JLabel ("Test2");
lblTest3 = new JLabel ("Test3");
lblTest4 = new JLabel ("Test4");
lblWeight1 = new JLabel ("Weight1");
lblWeight2 = new JLabel ("Weight2");
lblWeight3 = new JLabel ("Weight3");
lblWeight4 = new JLabel ("Weight4");
txtTest1 = new JTextField (5);
txtTest2 = new JTextField (5);
txtTest3 = new JTextField (5);
txtWeight1 = new JTextField (5);
txtWeight2 = new JTextField (5);
txtWeight3 = new JTextField (5);
txtWeight4 = new JTextField (5);
txtTest4 = new JTextField (5);
//Add all components to panel
pane.add (lblTest1);
pane.add (lblTest2);
pane.add (lblTest3);
pane.add (lblTest4);
pane.add (txtTest1);
pane.add (txtTest2);
pane.add (txtTest3);
pane.add (txtTest4);
pane.add (btnCalculate);
pane.add (lblWeight1);
pane.add (lblWeight2);
pane.add (lblWeight3);
pane.add (lblWeight4);
pane.add (txtWeight1);
pane.add (txtWeight2);
pane.add (txtWeight3);
pane.add (txtWeight4);
//Place all components
lblTest1.setBounds (insets.left + 5, insets.top + 5, lblTest1.getPreferredSize().width, lblTest1.getPreferredSize().height);
txtTest1.setBounds (lblTest1.getX() + lblTest1.getWidth() + 5, insets.top + 5, txtTest1.getPreferredSize().width, txtTest1.getPreferredSize().height);
lblTest2.setBounds (txtTest1.getX() + txtTest1.getWidth() + 8, insets.top + 5, lblTest2.getPreferredSize().width, lblTest2.getPreferredSize().height);
txtTest2.setBounds (lblTest2.getX() + lblTest2.getWidth() + 8, insets.top + 5, txtTest2.getPreferredSize().width, txtTest2.getPreferredSize().height);
lblTest3.setBounds (txtTest2.getX() + txtTest2.getWidth() + 5, insets.top + 5, lblTest3.getPreferredSize().width, lblTest3.getPreferredSize().height);
txtTest3.setBounds (lblTest3.getX() + lblTest3.getWidth() + 5, insets.top + 5, txtTest3.getPreferredSize().width, txtTest3.getPreferredSize().height);
lblTest4.setBounds (txtTest3.getX() + txtTest3.getWidth() + 5, insets.top + 5, lblTest4.getPreferredSize().width, lblTest4.getPreferredSize().height);
txtTest4.setBounds (lblTest4.getX() + lblTest4.getWidth() + 5, insets.top + 5, txtTest4.getPreferredSize().width, txtTest4.getPreferredSize().height);
btnCalculate.setBounds (txtTest4.getX() + txtTest4.getWidth() + 5, insets.top + 5, btnCalculate.getPreferredSize().width, btnCalculate.getPreferredSize().height);
lblWeight1.setBounds (insets.left + 5, insets.top + 30, lblWeight1.getPreferredSize().width, lblWeight1.getPreferredSize().height);
txtWeight1.setBounds (lblWeight1.getX() + lblWeight1.getWidth() + 5, insets.top + 30, txtWeight1.getPreferredSize().width, txtWeight1.getPreferredSize().height);
lblWeight2.setBounds (txtWeight1.getX() + txtWeight1.getWidth() + 5, insets.top + 30, txtWeight1.getPreferredSize().width, txtWeight1.getPreferredSize().height);
txtWeight2.setBounds (lblWeight2.getX() + lblWeight2.getWidth() + 10, insets.top + 30, txtWeight2.getPreferredSize().width, txtWeight2.getPreferredSize().height);
lblWeight3.setBounds (txtWeight2.getX() + txtWeight2.getWidth() + 10, insets.top + 30, txtWeight2.getPreferredSize().width, txtWeight2.getPreferredSize().height);
txtWeight3.setBounds (lblWeight3.getX() + lblWeight3.getWidth() + 10, insets.top + 30, txtWeight3.getPreferredSize().width, txtWeight3.getPreferredSize().height);
lblWeight4.setBounds (txtWeight3.getX() + txtWeight3.getWidth() + 15, insets.top + 30, txtWeight4.getPreferredSize().width, txtWeight3.getPreferredSize().height);
txtWeight4.setBounds (lblWeight4.getX() + lblWeight4.getWidth() + 15, insets.top + 30, txtWeight4.getPreferredSize().width, txtWeight4.getPreferredSize().height);
//Set frame visible
frame1.setVisible (true);
//Button's action
btnCalculate.addActionListener(new ActionListener()); //Register action
double Test1 = Double.parseDouble(txtTest1.getText());
double Test2 = Double.parseDouble(txtTest2.getText());
double Test3 = Double.parseDouble(txtTest3.getText());
double Test4 = Double.parseDouble(txtTest4.getText());
double Weight1 = Double.parseDouble (txtWeight1.getText());
double Weight2 = Double.parseDouble(txtWeight2.getText());
double Weight3 = Double.parseDouble (txtWeight3.getText());
double Weight4 = Double.parseDouble(txtWeight4.getText());
}
public class btnCalculate implements ActionListener{
public void actionPerformed (ActionEvent e){
Average = ((Test1*Weight1)+(Test2*Weight2)+(Test3*Weight3)+(Test4*Weight4));
Average = ((Test1*Weight1)+(Test2*Weight2)+(Test3*Weight3)+(Test4*Weight4));
System.out.println(Average);
}
}
}
答案 0 :(得分：0)
将您的actionPerformed（）方法放在侦听器构造函数旁边，如下所示：
btnCalculate.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Average = ((Test1*Weight1)+(Test2*Weight2)+(Test3*Weight3)+(Test4*Weight4));
}
} );
您当前的代码正在创建一个名为btnCalculate但未被使用的新类。您想要将侦听器分配给 Jbutton对象 btnCalculate。
或者，我相信你可以写：
btnCalculate.addActionListener(new btnCalculate());
但是，这是不好的形式，因为您使用相同的名称来引用两个单独的实体。
答案 1 :(得分：0)
你的变量不是静态的你不能调用外部的main方法，你不能简单地调用一个接口的构造函数，你必须覆盖你调用它的任何地方，所以删除那个类并将其添加到新的ActionListener（）所在的位置
public static void main(String args[]) {
JFrame frame1;
Container pane;
JButton btnCalculate;
JLabel lblTest1, lblWeight1, lblWeight2, lblWeight3, lblWeight4, lblTest2, lblTest3, lblTest4;
JTextField txtTest1, txtTest2, txtTest3, txtTest4, txtWeight1, txtWeight2, txtWeight3, txtWeight4;
Insets insets;
double Average;
//Set Look and Feel
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException e) {
} catch (InstantiationException e) {
} catch (IllegalAccessException e) {
} catch (UnsupportedLookAndFeelException e) {
}
//Create the frame
frame1 = new JFrame("Sample GUI Application");
frame1.setSize(800, 200);
pane = frame1.getContentPane();
insets = pane.getInsets();
pane.setLayout(null);
//Create controls
btnCalculate = new JButton("Calculate");
lblTest1 = new JLabel("Test1:");
lblTest2 = new JLabel("Test2");
lblTest3 = new JLabel("Test3");
lblTest4 = new JLabel("Test4");
lblWeight1 = new JLabel("Weight1");
lblWeight2 = new JLabel("Weight2");
lblWeight3 = new JLabel("Weight3");
lblWeight4 = new JLabel("Weight4");
txtTest1 = new JTextField(5);
txtTest2 = new JTextField(5);
txtTest3 = new JTextField(5);
txtWeight1 = new JTextField(5);
txtWeight2 = new JTextField(5);
txtWeight3 = new JTextField(5);
txtWeight4 = new JTextField(5);
txtTest4 = new JTextField(5);
//Add all components to panel
pane.add(lblTest1);
pane.add(lblTest2);
pane.add(lblTest3);
pane.add(lblTest4);
pane.add(txtTest1);
pane.add(txtTest2);
pane.add(txtTest3);
pane.add(txtTest4);
pane.add(btnCalculate);
pane.add(lblWeight1);
pane.add(lblWeight2);
pane.add(lblWeight3);
pane.add(lblWeight4);
pane.add(txtWeight1);
pane.add(txtWeight2);
pane.add(txtWeight3);
pane.add(txtWeight4);
//Place all components
lblTest1.setBounds(insets.left + 5, insets.top + 5, lblTest1.getPreferredSize().width, lblTest1.getPreferredSize().height);
txtTest1.setBounds(lblTest1.getX() + lblTest1.getWidth() + 5, insets.top + 5, txtTest1.getPreferredSize().width, txtTest1.getPreferredSize().height);
lblTest2.setBounds(txtTest1.getX() + txtTest1.getWidth() + 8, insets.top + 5, lblTest2.getPreferredSize().width, lblTest2.getPreferredSize().height);
txtTest2.setBounds(lblTest2.getX() + lblTest2.getWidth() + 8, insets.top + 5, txtTest2.getPreferredSize().width, txtTest2.getPreferredSize().height);
lblTest3.setBounds(txtTest2.getX() + txtTest2.getWidth() + 5, insets.top + 5, lblTest3.getPreferredSize().width, lblTest3.getPreferredSize().height);
txtTest3.setBounds(lblTest3.getX() + lblTest3.getWidth() + 5, insets.top + 5, txtTest3.getPreferredSize().width, txtTest3.getPreferredSize().height);
lblTest4.setBounds(txtTest3.getX() + txtTest3.getWidth() + 5, insets.top + 5, lblTest4.getPreferredSize().width, lblTest4.getPreferredSize().height);
txtTest4.setBounds(lblTest4.getX() + lblTest4.getWidth() + 5, insets.top + 5, txtTest4.getPreferredSize().width, txtTest4.getPreferredSize().height);
btnCalculate.setBounds(txtTest4.getX() + txtTest4.getWidth() + 5, insets.top + 5, btnCalculate.getPreferredSize().width, btnCalculate.getPreferredSize().height);
lblWeight1.setBounds(insets.left + 5, insets.top + 30, lblWeight1.getPreferredSize().width, lblWeight1.getPreferredSize().height);
txtWeight1.setBounds(lblWeight1.getX() + lblWeight1.getWidth() + 5, insets.top + 30, txtWeight1.getPreferredSize().width, txtWeight1.getPreferredSize().height);
lblWeight2.setBounds(txtWeight1.getX() + txtWeight1.getWidth() + 5, insets.top + 30, txtWeight1.getPreferredSize().width, txtWeight1.getPreferredSize().height);
txtWeight2.setBounds(lblWeight2.getX() + lblWeight2.getWidth() + 10, insets.top + 30, txtWeight2.getPreferredSize().width, txtWeight2.getPreferredSize().height);
lblWeight3.setBounds(txtWeight2.getX() + txtWeight2.getWidth() + 10, insets.top + 30, txtWeight2.getPreferredSize().width, txtWeight2.getPreferredSize().height);
txtWeight3.setBounds(lblWeight3.getX() + lblWeight3.getWidth() + 10, insets.top + 30, txtWeight3.getPreferredSize().width, txtWeight3.getPreferredSize().height);
lblWeight4.setBounds(txtWeight3.getX() + txtWeight3.getWidth() + 15, insets.top + 30, txtWeight4.getPreferredSize().width, txtWeight3.getPreferredSize().height);
txtWeight4.setBounds(lblWeight4.getX() + lblWeight4.getWidth() + 15, insets.top + 30, txtWeight4.getPreferredSize().width, txtWeight4.getPreferredSize().height);
//Set frame visible
frame1.setVisible(true);
//Button's action
btnCalculate.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e) {
// you won't have access to your variables here unless they are final, because this is an inner class, I sugest you do not make a gui inside the static main.
}
}); //Register action
double Test1 = Double.parseDouble(txtTest1.getText());
double Test2 = Double.parseDouble(txtTest2.getText());
double Test3 = Double.parseDouble(txtTest3.getText());
double Test4 = Double.parseDouble(txtTest4.getText());
double Weight1 = Double.parseDouble(txtWeight1.getText());
double Weight2 = Double.parseDouble(txtWeight2.getText());
double Weight3 = Double.parseDouble(txtWeight3.getText());
double Weight4 = Double.parseDouble(txtWeight4.getText());
}
不要忘记静态修饰符和接口的基本规则。
答案 2 :(得分：0)
就像肖恩斯科特说的那样。
首先，addActionListener（）的参数应该是实现ActionListner的内部类。 此外，您不应同时为变量和类赋予相同的名称。
btnCalculate.addActionListener(new btnCalculate()) // Again, you shouldn't name inner class the same way as JButton variable...