wmd*_*zyl 6 java swing dynamic jscrollpane jcheckbox
编辑:使用下面提供的解决方案,我已经更改了代码,在JScrollPane中有一个JPanel.使用JButton我将JCheckBoxes添加到JScrollPane内的JPanel.这是一个问题,因为JScrollPanecan只接受一个JComponent.解决了其余问题,在JScrollPane中为JPanel设置了gridlayout.为了后代,我在这里保留了原来的问题:
原始问题:我正在尝试动态创建JCheckBox并将它们添加到JScrollPane,但唉,我收效甚微.我将其简化为单一的概念验证实现.
我在JFrame中有一个JScrollPaneon JPanel.同样在JPanel上,我添加了一个按钮,可以在单击时将JCheckBox添加到JScrollPane.应该够简单.按钮内的代码如下:
private void addCheckBoxActionPerformed(java.awt.event.ActionEvent evt) {
JCheckBox cb = new JCheckBox("New CheckBox");
jScrollPaneCheckBoxes.add(cb);
jScrollPaneCheckBoxes.revalidate();
}
代码运行似乎没有错误.我没有例外,使用调试器显示JCheckBox实际上已添加到JScrollPane.不幸的是,应用程序中没有显示任何内容 我需要指导在哪里寻找问题.
这是您可以运行的快速代码.不幸的是,我使用Netbeans和它的GUI设计器将它们放在一起,因此它比它需要的时间长,特别是生成的代码.专注于方法jButton1ActionPerformed,这就是上面代码的来源.
编辑:此代码现在做我需要它.:-)
package dynamiccheckboxsscce;
import javax.swing.JCheckBox;
public class Main extends javax.swing.JFrame {
/**
* Creates new form Main
*/
public Main() {
initComponents();
}
@SuppressWarnings("unchecked")
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jPanel1 = new javax.swing.JPanel();
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jScrollPane1.setHorizontalScrollBarPolicy(javax.swing.ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
jScrollPane1.setPreferredSize(new java.awt.Dimension(250, 250));
jPanel1.setPreferredSize(new java.awt.Dimension(300, 250));
jPanel1.setLayout(new java.awt.GridLayout(0, 2, 10, 10));
jScrollPane1.setViewportView(jPanel1);
jButton1.setText("Add Checkbox");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 309, Short.MAX_VALUE)
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 0, Short.MAX_VALUE)
.addComponent(jButton1)
.addGap(112, 112, 112)))));
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 11, Short.MAX_VALUE)
.addComponent(jButton1)
.addContainerGap()));
pack();
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
JCheckBox cb = new JCheckBox("New CheckBox");
jPanel1.add(cb);
jPanel1.revalidate();
jPanel1.repaint();
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Main.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Main.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Main.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Main.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Main().setVisible(true);
}
});
}
private javax.swing.JButton jButton1;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
}
提前致谢.
没有发布SSCCE你必须接受JScrollPane被指定只嵌套一个JComponent,
如果你想添加更多的是一个JComponent到JScrollPane时,把那里的JPanel,然后添加一个新JComponent的JPanel,而不是JScrollPane
编辑
你必须将正确的LayoutManager设置为JPanel
你要将JPanel添加到JScrollPane
例如(不使用built_in设计器,甚至安全时间...,需要关于使用SwingFramework和Swing的最佳知识,我对普通Swing感到满意)
码
import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class AddJCheckBoxToJScrollPane {
private static final long serialVersionUID = 1L;
private JFrame frame = new JFrame();
private JButton jButton1;
private JPanel jPanel1;
private JScrollPane jScrollPane1;
public AddJCheckBoxToJScrollPane() {
jPanel1 = new JPanel();
jPanel1.setLayout(new GridLayout(0, 2, 10, 10));
jScrollPane1 = new JScrollPane(jPanel1);
jButton1 = new JButton("Add Checkbox");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
JCheckBox cb = new JCheckBox("New CheckBox");
jPanel1.add(cb);
jPanel1.revalidate();
jPanel1.repaint();
}
});
frame.add(jScrollPane1);
frame.add(jButton1, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300, 200);
//frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String args[]) {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new AddJCheckBoxToJScrollPane();
}
});
}
}