一番上のJPanel（これは基本的に一番上の親JPanel）の高さを、その子JPanelの高さにサイズ変更するのに問題があります。その結果、一番上のJPanelをグリッドレイアウトに配置すると、親JPanelによって占有されている子JPanelの下に余分なギャップがあります。私がやりたいのは、このギャップをなくして、一番上のJPanelのサイズが子のJPanelと同じサイズになるようにすることです。
基本的に、親JPanelはJPanelを拡張するクラスです。子JPanelのサイズを使用して、子JPanelのサイズにサイズ変更しようとしましたが、結果は同じです。
this.setSize(childJPanel.getSize());
明確にするために、私はMatisseビジュアルエディターを使用してこのトップJPanel（GroupLayoutに設定）を編集し、このトップJPanelをGridLayoutを使用して別のJPanelに配置しています。
トップJPanelをその子JPanelの高さにサイズ変更するように強制するにはどうすればよいですか？
コード：
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package helloworld;
/**
*
* @author Justin
*/
public class FooPanel extends javax.swing.JPanel {
/**
* Creates new form NewJPanel
*/
public FooPanel() {
initComponents();
}
/**
* 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() {
jPanel1 = new javax.swing.JPanel();
jLabel2 = new javax.swing.JLabel();
jPanel1.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
jLabel2.setText("HELLOWORLD");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel2)
.addContainerGap(122, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel2)
.addContainerGap(45, Short.MAX_VALUE))
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
);
}// </editor-fold>
// Variables declaration - do not modify
private javax.swing.JLabel jLabel2;
private javax.swing.JPanel jPanel1;
// End of variables declaration
}
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package helloworld;
import java.awt.GridLayout;
import javax.swing.border.EmptyBorder;
/**
*
* @author Justin
*/
public class NewJApplet extends javax.swing.JApplet {
/**
* Initializes the applet NewJApplet
*/
@Override
public void init() {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
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(NewJApplet.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(NewJApplet.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(NewJApplet.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(NewJApplet.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the applet */
try {
java.awt.EventQueue.invokeAndWait(new Runnable() {
public void run() {
initComponents();
FooPanel panel1 = new FooPanel();
FooPanel panel2 = new FooPanel();
FooPanel panel3 = new FooPanel();
myPanel.setBorder(new EmptyBorder(5, 5, 5, 5) );
myPanel.setLayout(new GridLayout(0,1));
myPanel.add(panel1);
myPanel.add(panel2);
myPanel.add(panel3);
}
});
} catch (Exception ex) {
ex.printStackTrace();
}
}
/**
* This method is called from within the init() method 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() {
myPanel = new javax.swing.JPanel();
javax.swing.GroupLayout myPanelLayout = new javax.swing.GroupLayout(myPanel);
myPanel.setLayout(myPanelLayout);
myPanelLayout.setHorizontalGroup(
myPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 200, Short.MAX_VALUE)
);
myPanelLayout.setVerticalGroup(
myPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(myPanel, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 200, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(myPanel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
}// </editor-fold>
// Variables declaration - do not modify
private javax.swing.JPanel myPanel;
// End of variables declaration
}
結果：
