关于Swing的一个非常基础的问题


NewJFrame.java
import javax.swing.SwingUtilities;/*
 * charset:UTF-8
 * license
 */
/**
 *
 * @author Administrator
 */
public class NewJFrame extends javax.swing.JFrame {    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() {
        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">//GEN-BEGIN:initComponents
    private void initComponents() {        jToggleButton1 = new javax.swing.JToggleButton();        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);        jToggleButton1.setText("jToggleButton1");        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(119, 119, 119)
                .addComponent(jToggleButton1)
                .addContainerGap(164, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(101, 101, 101)
                .addComponent(jToggleButton1)
                .addContainerGap(176, Short.MAX_VALUE))
        );        pack();
    }// </editor-fold>//GEN-END:initComponents    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* 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 ("Windows".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>        /* Create and display the form */
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JToggleButton jToggleButton1;
    // End of variables declaration//GEN-END:variables
}NewJFrame.form<?xml version="1.0" encoding="UTF-8" ?><Form version="1.3" maxVersion="1.8" type="org.netbeans.modules.form.forminfo.JFrameFormInfo">
  <Properties>
    <Property name="defaultCloseOperation" type="int" value="3"/>
  </Properties>
  <SyntheticProperties>
    <SyntheticProperty name="formSizePolicy" type="int" value="1"/>
    <SyntheticProperty name="generateCenter" type="boolean" value="false"/>
  </SyntheticProperties>
  <AuxValues>
    <AuxValue name="FormSettings_autoResourcing" type="java.lang.Integer" value="0"/>
    <AuxValue name="FormSettings_autoSetComponentName" type="java.lang.Boolean" value="false"/>
    <AuxValue name="FormSettings_generateFQN" type="java.lang.Boolean" value="true"/>
    <AuxValue name="FormSettings_generateMnemonicsCode" type="java.lang.Boolean" value="false"/>
    <AuxValue name="FormSettings_i18nAutoMode" type="java.lang.Boolean" value="false"/>
    <AuxValue name="FormSettings_layoutCodeTarget" type="java.lang.Integer" value="1"/>
    <AuxValue name="FormSettings_listenerGenerationStyle" type="java.lang.Integer" value="0"/>
    <AuxValue name="FormSettings_variablesLocal" type="java.lang.Boolean" value="false"/>
    <AuxValue name="FormSettings_variablesModifier" type="java.lang.Integer" value="2"/>
  </AuxValues>  <Layout>
    <DimensionLayout dim="0">
      <Group type="103" groupAlignment="0" attributes="0">
          <Group type="102" alignment="0" attributes="0">
              <EmptySpace min="-2" pref="119" max="-2" attributes="0"/>
              <Component id="jToggleButton1" min="-2" max="-2" attributes="0"/>
              <EmptySpace pref="164" max="32767" attributes="0"/>
          </Group>
      </Group>
    </DimensionLayout>
    <DimensionLayout dim="1">
      <Group type="103" groupAlignment="0" attributes="0">
          <Group type="102" alignment="0" attributes="0">
              <EmptySpace min="-2" pref="101" max="-2" attributes="0"/>
              <Component id="jToggleButton1" min="-2" max="-2" attributes="0"/>
              <EmptySpace pref="176" max="32767" attributes="0"/>
          </Group>
      </Group>
    </DimensionLayout>
  </Layout>
  <SubComponents>
    <Component class="javax.swing.JToggleButton" name="jToggleButton1">
      <Properties>
        <Property name="text" type="java.lang.String" value="jToggleButton1"/>
      </Properties>
    </Component>
  </SubComponents>
</Form>