我有一个关于一些原始图形的问题。
一般来说，我是 Java 图形和图形用户界面构建的新手，所以我遇到了很多问题。
我正在使用 Netbeans 6.9.1。基本上，里面有一个主框架和一个面板。我想在面板内绘制图表。好吧，问题是要这样做吗？下面是三个类的代码(大部分是自动生成的):
package graphics;
import org.jdesktop.application.Action;
import org.jdesktop.application.ResourceMap;
import org.jdesktop.application.SingleFrameApplication;
import org.jdesktop.application.FrameView;
import org.jdesktop.application.TaskMonitor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;
import javax.swing.Icon;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
/**
* The application's main frame.
*/
public class GraphicsView extends FrameView {
public GraphicsView(SingleFrameApplication app) {
super(app);
initComponents();
jPanel1.add(new Graph());
// status bar initialization - message timeout, idle icon and busy animation, etc
ResourceMap resourceMap = getResourceMap();
int messageTimeout = resourceMap.getInteger("StatusBar.messageTimeout");
messageTimer = new Timer(messageTimeout, new ActionListener() {
public void actionPerformed(ActionEvent e) {
statusMessageLabel.setText("");
}
});
messageTimer.setRepeats(false);
int busyAnimationRate = resourceMap.getInteger("StatusBar.busyAnimationRate");
for (int i = 0; i < busyIcons.length; i++) {
busyIcons[i] = resourceMap.getIcon("StatusBar.busyIcons[" + i + "]");
}
busyIconTimer = new Timer(busyAnimationRate, new ActionListener() {
public void actionPerformed(ActionEvent e) {
busyIconIndex = (busyIconIndex + 1) % busyIcons.length;
statusAnimationLabel.setIcon(busyIcons[busyIconIndex]);
}
});
idleIcon = resourceMap.getIcon("StatusBar.idleIcon");
statusAnimationLabel.setIcon(idleIcon);
progressBar.setVisible(false);
// connecting action tasks to status bar via TaskMonitor
TaskMonitor taskMonitor = new TaskMonitor(getApplication().getContext());
taskMonitor.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
public void propertyChange(java.beans.PropertyChangeEvent evt) {
String propertyName = evt.getPropertyName();
if ("started".equals(propertyName)) {
if (!busyIconTimer.isRunning()) {
statusAnimationLabel.setIcon(busyIcons[0]);
busyIconIndex = 0;
busyIconTimer.start();
}
progressBar.setVisible(true);
progressBar.setIndeterminate(true);
} else if ("done".equals(propertyName)) {
busyIconTimer.stop();
statusAnimationLabel.setIcon(idleIcon);
progressBar.setVisible(false);
progressBar.setValue(0);
} else if ("message".equals(propertyName)) {
String text = (String)(evt.getNewValue());
statusMessageLabel.setText((text == null) ? "" : text);
messageTimer.restart();
} else if ("progress".equals(propertyName)) {
int value = (Integer)(evt.getNewValue());
progressBar.setVisible(true);
progressBar.setIndeterminate(false);
progressBar.setValue(value);
}
}
});
}
@Action
public void showAboutBox() {
if (aboutBox == null) {
JFrame mainFrame = GraphicsApp.getApplication().getMainFrame();
aboutBox = new GraphicsAboutBox(mainFrame);
aboutBox.setLocationRelativeTo(mainFrame);
}
GraphicsApp.getApplication().show(aboutBox);
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
mainPanel = new javax.swing.JPanel();
jPanel1 = new javax.swing.JPanel();
menuBar = new javax.swing.JMenuBar();
javax.swing.JMenu fileMenu = new javax.swing.JMenu();
javax.swing.JMenuItem exitMenuItem = new javax.swing.JMenuItem();
javax.swing.JMenu helpMenu = new javax.swing.JMenu();
javax.swing.JMenuItem aboutMenuItem = new javax.swing.JMenuItem();
statusPanel = new javax.swing.JPanel();
javax.swing.JSeparator statusPanelSeparator = new javax.swing.JSeparator();
statusMessageLabel = new javax.swing.JLabel();
statusAnimationLabel = new javax.swing.JLabel();
progressBar = new javax.swing.JProgressBar();
mainPanel.setName("mainPanel"); // NOI18N
jPanel1.setName("jPanel1"); // NOI18N
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 380, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 229, Short.MAX_VALUE)
);
javax.swing.GroupLayout mainPanelLayout = new javax.swing.GroupLayout(mainPanel);
mainPanel.setLayout(mainPanelLayout);
mainPanelLayout.setHorizontalGroup(
mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(mainPanelLayout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
mainPanelLayout.setVerticalGroup(
mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(mainPanelLayout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
menuBar.setName("menuBar"); // NOI18N
org.jdesktop.application.ResourceMap resourceMap = org.jdesktop.application.Application.getInstance(graphics.GraphicsApp.class).getContext().getResourceMap(GraphicsView.class);
fileMenu.setText(resourceMap.getString("fileMenu.text")); // NOI18N
fileMenu.setName("fileMenu"); // NOI18N
javax.swing.ActionMap actionMap = org.jdesktop.application.Application.getInstance(graphics.GraphicsApp.class).getContext().getActionMap(GraphicsView.class, this);
exitMenuItem.setAction(actionMap.get("quit")); // NOI18N
exitMenuItem.setName("exitMenuItem"); // NOI18N
fileMenu.add(exitMenuItem);
menuBar.add(fileMenu);
helpMenu.setText(resourceMap.getString("helpMenu.text")); // NOI18N
helpMenu.setName("helpMenu"); // NOI18N
aboutMenuItem.setAction(actionMap.get("showAboutBox")); // NOI18N
aboutMenuItem.setName("aboutMenuItem"); // NOI18N
helpMenu.add(aboutMenuItem);
menuBar.add(helpMenu);
statusPanel.setName("statusPanel"); // NOI18N
statusPanelSeparator.setName("statusPanelSeparator"); // NOI18N
statusMessageLabel.setName("statusMessageLabel"); // NOI18N
statusAnimationLabel.setHorizontalAlignment(javax.swing.SwingConstants.LEFT);
statusAnimationLabel.setName("statusAnimationLabel"); // NOI18N
progressBar.setName("progressBar"); // NOI18N
javax.swing.GroupLayout statusPanelLayout = new javax.swing.GroupLayout(statusPanel);
statusPanel.setLayout(statusPanelLayout);
statusPanelLayout.setHorizontalGroup(
statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(statusPanelSeparator, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
.addGroup(statusPanelLayout.createSequentialGroup()
.addContainerGap()
.addComponent(statusMessageLabel)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 230, Short.MAX_VALUE)
.addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(statusAnimationLabel)
.addContainerGap())
);
statusPanelLayout.setVerticalGroup(
statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(statusPanelLayout.createSequentialGroup()
.addComponent(statusPanelSeparator, javax.swing.GroupLayout.PREFERRED_SIZE, 2, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(statusMessageLabel)
.addComponent(statusAnimationLabel)
.addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(3, 3, 3))
);
setComponent(mainPanel);
setMenuBar(menuBar);
setStatusBar(statusPanel);
}// </editor-fold>
// Variables declaration - do not modify
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel mainPanel;
private javax.swing.JMenuBar menuBar;
private javax.swing.JProgressBar progressBar;
private javax.swing.JLabel statusAnimationLabel;
private javax.swing.JLabel statusMessageLabel;
private javax.swing.JPanel statusPanel;
// End of variables declaration
private final Timer messageTimer;
private final Timer busyIconTimer;
private final Icon idleIcon;
private final Icon[] busyIcons = new Icon[15];
private int busyIconIndex = 0;
private JDialog aboutBox;
}
所以，这里我只添加了
jPanel1.add(new Graph());
接下来是主类:
package graphics;
import org.jdesktop.application.Application;
import org.jdesktop.application.SingleFrameApplication;
/**
* The main class of the application.
*/
public class GraphicsApp extends SingleFrameApplication {
/**
* At startup create and show the main frame of the application.
*/
@Override protected void startup() {
show(new GraphicsView(this));
}
/**
* This method is to initialize the specified window by injecting resources.
* Windows shown in our application come fully initialized from the GUI
* builder, so this additional configuration is not needed.
*/
@Override protected void configureWindow(java.awt.Window root) {
}
/**
* A convenient static getter for the application instance.
* @return the instance of GraphicsApp
*/
public static GraphicsApp getApplication() {
return Application.getInstance(GraphicsApp.class);
}
/**
* Main method launching the application.
*/
public static void main(String[] args) {
launch(GraphicsApp.class, args);
}
}
最后一节课是图形本身:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package graphics;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import javax.swing.JPanel;
public class Graph extends JPanel{
int[] data = {
21, 14, 18, 03, 86, 88, 74, 87, 54, 77,
61, 55, 48, 60, 49, 36, 38, 27, 20, 18
};
final int PAD = 20;
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int w = getWidth();
int h = getHeight();
// Draw ordinate.
g2.draw(new Line2D.Double(PAD, PAD, PAD, h-PAD));
// Draw abcissa.
g2.draw(new Line2D.Double(PAD, h-PAD, w-PAD, h-PAD));
double xInc = (double)(w - 2*PAD)/(data.length-1);
double scale = (double)(h - 2*PAD)/getMax();
// Mark data points.
g2.setPaint(Color.red);
for(int i = 0; i < data.length; i++) {
double x = PAD + i*xInc;
double y = h - PAD - scale*data[i];
g2.fill(new Ellipse2D.Double(x-2, y-2, 4, 4));
}
}
private int getMax() {
int max = -Integer.MAX_VALUE;
for(int i = 0; i < data.length; i++) {
if(data[i] > max)
max = data[i];
}
return max;
}
}
我有几个问题:
(a) 如何在 jPanel1 中显示图形？
(b) 初始化图形组件的良好做法是什么？我的意思是，调用 graph() 的最佳位置在哪里？
(c) 对于不同的应用程序，我使用 jfreechart 绘制图形，然后将它们转储到 .jpeg 文件。我可以使用 jfreechart 构建图表并直接在页面中显示吗？
非常感谢您!
最佳答案
一些答案:
(a) 让 jPanel1 使用 BorderLayout 作为其布局管理器，并在 BorderLayout.CENTER 位置将图形 JPanel 添加到 jPanel1。
(b) 我不清楚你在这里问什么。在需要时构建对象。
(c) 是的。 JFreeChart 的图形组件扩展了 Swing 组件，我相信 JPanel(或者 JComponent)，所以你应该能够将它们作为组件直接添加到你的 GUI 中，只要(这是关键)你的组件充当容器，那就是持有图表的人，使用正确的布局管理器。如果您还没有这样做，您应该阅读有关“在容器中布置组件”的 Swing 教程，因为它的信息是成功的关键。
我的最终建议(目前)是放弃 NetBeans 代码生成并手动创建 Swing 代码。这确实是学习 Swing 的最佳方式。
祝你好运!
关于java - Netbeans 中 jPanel 中的二维图形，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4373016/