所以我有一个明天到期的程序，只要我能够弄清楚我的代码有什么问题，我就坚持了。第一个也是最大的问题让我沉寂了一段时间是我的重置按钮动作监听器。它只是不能正确编译并说没有找到价值？我评论了它，所以我至少可以运行你应该能够清楚地看到我评论它们的程序。第二个问题是我必须让一个文本字段在移动它们时显示两个滑块之间的MAX值，另一个给我两个滑块之间的TOTAL值。老实说，我不知道该怎样做的逻辑结束，只是简单地将两个jtextfields连接到左滑块。为此，我希望推动正确的方向？如果你给我代码，我将非常感激，但我也想解释它为什么工作/我的代码有什么问题。谢谢！
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
/**
This class displays a window with a slider component.
The user can slide the left or right slider. As the
sliders are adjusted it displays the maximum sound
level coming from either slider as well as the total.
*/
public class SoundLevels extends JFrame
{
private JLabel label1, label2, label3, label4; // Message labels
private JTextField maxSound; // Max Sound Level
private JTextField totalSound; // Total Sound Level
private JPanel mpanel; // Max sound level panel
private JPanel tpanel; // Total sound level panel
private JPanel sliderPanel1; // Slider panel 1
private JPanel sliderPanel2; // Slider panel 2
private JPanel resetpanel; // Reset button panel
private JSlider slider1; // Left sound adjuster
private JSlider slider2; // Right sound adjuster
private JButton resetButton; // Reset button
/**
Constructor
*/
public SoundLevels()
{
// Set the title.
setTitle("Sound Levels");
// Specify an action for the close button.
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Creates reset button
resetButton = new JButton("Reset");
// Create the message labels.
label1 = new JLabel("Left: ");
label2 = new JLabel("Right: ");
label3 = new JLabel("Max: ");
label4 = new JLabel("Total: ");
// Create the read-only text fields.
maxSound = new JTextField("0", 10);
maxSound.setEditable(false);
totalSound = new JTextField("0", 10);
totalSound.setEditable(false);
// Create the slider.
slider1 = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);
slider2 = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);
slider1.addChangeListener(new SliderListener());
// Create panels and place the components in them.
mpanel = new JPanel();
resetpanel = new JPanel();
tpanel = new JPanel();
sliderPanel1 = new JPanel();
sliderPanel2 = new JPanel();
//Add components to panels
mpanel.add(label1);
mpanel.add(maxSound);
tpanel.add(label2);
tpanel.add(totalSound);
sliderPanel1.add(label1);
sliderPanel1.add(slider1);
sliderPanel2.add(label2);
sliderPanel2.add(slider2);
resetpanel.add(resetButton);
// Initialize event listener
// resetButton.addActionListener(new ResetButtonListener());
// Sets window to a border layout format.
setLayout(new GridLayout(1, 5));
// Add the panels to the content pane.
add(sliderPanel1);
add(sliderPanel2);
add(resetpanel);
add(mpanel);
add(tpanel);
// Pack and display the frame.
pack();
setVisible(true);
}
/**
Private inner class that handles the event when
the user clicks the Reset button.
*/
/* COMMENTED THIS OUT SO IT AT LEAST RUNS
private class ResetButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
// Set the panel's background to red.
max = 0; //should reset sliders to 0
total = 0; //should reset sliders to 0
}
}
*/
/**
Private inner class to handle the change events
that are generated when the slider is moved.
*/
private class SliderListener implements ChangeListener
{
public void stateChanged(ChangeEvent e)
{
int max, total;
// Get the slider value.
max = slider1.getValue();
total = slider1.getValue();
// Store the total sound level in its display field.
totalSound.setText(Integer.toString(total));
// Store the max sound level in its display field.
maxSound.setText(Integer.toString(max));
}
}
/*
The main method creates an instance of the
class, which displays a window with a slider.
*/
public static void main(String[] args)
{
new SoundLevels();
}
}
答案 0 :(得分：2)
我建议2次更改。
slider1.addChangeListener(new SliderListener());
slider2.addChangeListener(new SliderListener()); // newly added
＆安培;在听众中：
// Get the slider value.
max = slider1.getValue();
total = slider2.getValue(); // change from 1 -> 2
我的操作私有重置按钮侦听器类有什么问题？
这是关于两个int属性的范围和可见性。请考虑此代码，但请注意，执行的操作不会更改滑块值，这可能会让用户感到困惑。
// class level attributes that are visible to both
// ResetButtonListener & ResetButtonListener
private int max, total;
/**
Private inner class that handles the event when
the user clicks the Reset button.
*/
private class ResetButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
// Set the panel's background to red.
max = 0; //should reset sliders to 0
total = 0; //should reset sliders to 0
}
}
/**
Private inner class to handle the change events
that are generated when the slider is moved.
*/
private class SliderListener implements ChangeListener
{
public void stateChanged(ChangeEvent e)
{
// Get the slider value.
max = slider1.getValue();
total = slider2.getValue();
// Store the total sound level in its display field.
totalSound.setText(Integer.toString(total));
// Store the max sound level in its display field.
maxSound.setText(Integer.toString(max));
}
}
答案 1 :(得分：2)
我改变的是为两个滑块添加一个监听器 -
slider1.addChangeListener(new SliderListener());
slider2.addChangeListener(new SliderListener());
并且还对滑块侦听器进行了更改 -
private class SliderListener implements ChangeListener {
public void stateChanged(ChangeEvent e) {
int max = 0;
int total = 0;
// Get the slider value.
int slider1Val = slider1.getValue();
int slider2Val = slider2.getValue();
if (slider1Val > slider2Val) {
max = slider1Val;
} else {
max = slider2Val;
}
total = slider2Val + slider1Val;
// Store the total sound level in its display field.
totalSound.setText(Integer.toString(total));
// Store the max sound level in its display field.
maxSound.setText(Integer.toString(max));
}
}
以下是整个编辑代码的方式 -
package org.dchan.orm;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
/**
* This class displays a window with a slider component. The user can slide the
* left or right slider. As the sliders are adjusted it displays the maximum
* sound level coming from either slider as well as the total.
*/
public class SoundLevels extends JFrame {
private JLabel label1, label2, label3, label4; // Message labels
private JTextField maxSound; // Max Sound Level
private JTextField totalSound; // Total Sound Level
private JPanel mpanel; // Max sound level panel
private JPanel tpanel; // Total sound level panel
private JPanel sliderPanel1; // Slider panel 1
private JPanel sliderPanel2; // Slider panel 2
private JPanel resetpanel; // Reset button panel
private JSlider slider1; // Left sound adjuster
private JSlider slider2; // Right sound adjuster
private JButton resetButton; // Reset button
/**
* Constructor
*/
public SoundLevels() {
// Set the title.
setTitle("Sound Levels");
// Specify an action for the close button.
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Creates reset button
resetButton = new JButton("Reset");
// Create the message labels.
label1 = new JLabel("Left: ");
label2 = new JLabel("Right: ");
label3 = new JLabel("Max: ");
label4 = new JLabel("Total: ");
// Create the read-only text fields.
maxSound = new JTextField("0", 10);
maxSound.setEditable(false);
totalSound = new JTextField("0", 10);
totalSound.setEditable(false);
// Create the slider.
slider1 = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);
slider2 = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);
slider1.addChangeListener(new SliderListener());
slider2.addChangeListener(new SliderListener());
// Create panels and place the components in them.
mpanel = new JPanel();
resetpanel = new JPanel();
tpanel = new JPanel();
sliderPanel1 = new JPanel();
sliderPanel2 = new JPanel();
// Add components to panels
mpanel.add(label1);
mpanel.add(maxSound);
tpanel.add(label2);
tpanel.add(totalSound);
sliderPanel1.add(label1);
sliderPanel1.add(slider1);
sliderPanel2.add(label2);
sliderPanel2.add(slider2);
resetpanel.add(resetButton);
// Initialize event listener
// resetButton.addActionListener(new ResetButtonListener());
// Sets window to a border layout format.
setLayout(new GridLayout(1, 5));
// Add the panels to the content pane.
add(sliderPanel1);
add(sliderPanel2);
add(resetpanel);
add(mpanel);
add(tpanel);
// Pack and display the frame.
pack();
setVisible(true);
}
/**
* Private inner class that handles the event when the user clicks the Reset
* button.
*/
/*
* COMMENTED THIS OUT SO IT AT LEAST RUNS
*/private class ResetButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
// Set the panel's background to red.
// max = 0; // should reset sliders to 0
// total = 0; // should reset sliders to 0
slider1.setValue(0);
slider2.setValue(0);
}
}
/*
*/
/**
* Private inner class to handle the change events that are generated when
* the slider is moved.
*/
private class SliderListener implements ChangeListener {
public void stateChanged(ChangeEvent e) {
int max = 0;
int total = 0;
// Get the slider value.
int slider1Val = slider1.getValue();
int slider2Val = slider2.getValue();
if (slider1Val > slider2Val) {
max = slider1Val;
} else {
max = slider2Val;
}
total = slider2Val + slider1Val;
// Store the total sound level in its display field.
totalSound.setText(Integer.toString(total));
// Store the max sound level in its display field.
maxSound.setText(Integer.toString(max));
}
}
/*
* The main method creates an instance of the class, which displays a window
* with a slider.
*/
public static void main(String[] args) {
new SoundLevels();
}
}
创建监听器需要一点逻辑理解。但是你需要理解，为了从两个滑块获得一个事件，应该将侦听器应用于两者。有关整个代码的要点，请访问 - https://gist.github.com/4193279。
为了将来参考，我建议您将问题分解为几个部分。