制作JFrame按钮可创建警报对话框.Java - Netbeans

Question

我使用NetBeans IDE,因为你可能知道有一个JFrame创建者插件(它预先安装)我用它来制作JFrames(因为我太懒了,我自己= /).如果在该JFrame中创建按钮,它将为事件代码生成一个区域.我想知道我需要输入什么代码来生成警报对话框.下面是创建swing/awt组件或JFrame时预先生成的内容:

    public class NewJFrame extends javax.swing.JFrame {

public NewJFrame() {
    initComponents();
}


@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jDialog2 = new javax.swing.JDialog();
    jButton1 = new javax.swing.JButton();

    javax.swing.GroupLayout jDialog2Layout = new javax.swing.GroupLayout(jDialog2.getContentPane());
    jDialog2.getContentPane().setLayout(jDialog2Layout);
    jDialog2Layout.setHorizontalGroup(
        jDialog2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 400, Short.MAX_VALUE)
    );
    jDialog2Layout.setVerticalGroup(
        jDialog2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 300, Short.MAX_VALUE)
    );

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setTitle(">:D");
    setResizable(false);
    addHierarchyBoundsListener(new java.awt.event.HierarchyBoundsListener() {
        public void ancestorMoved(java.awt.event.HierarchyEvent evt) {
            formAncestorMoved(evt);
        }
        public void ancestorResized(java.awt.event.HierarchyEvent evt) {
        }
    });

    jButton1.setText("Press Me :D");
    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)
        .addComponent(jButton1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 349, Short.MAX_VALUE)
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jButton1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 180, Short.MAX_VALUE)
    );

    pack();
    setLocationRelativeTo(null);
}// </editor-fold>                        

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    //This is the area for the code dialog code
}                                        

private void formAncestorMoved(java.awt.event.HierarchyEvent evt) {                                   
    // TODO add your handling code here:
}                                  

/**
 * @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 ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (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 */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new NewJFrame().setVisible(true);
        }
    });
}

你看到Button1ActionPerformed的东西???? 这就是代码的用武之地.我需要代码来创建一个新的警报对话框(javax.swing.JDialog)当按下它时.

提前致谢

Answer 1

听起来你可能想要一个JOptionPane消息对话框......

试试这个:

JOptionPane.showMessageDialog(null, "<your message here...>", "Alert", JOptionPane.ERROR_MESSAGE);

因此,对于您的情况,这是您的操作执行方法将如下所示:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    JOptionPane.showMessageDialog(null, "<your message here...>", "Alert", JOptionPane.ERROR_MESSAGE);        
}

注意,没有"变量"来存储JOptionPane对象,它是在类上调用的静态方法JOptionPane.每次你想要一个警报/确认/输入/等.对话框,您可以使用类的静态成员动态生成一个JOptionPane.

有关详细信息,请参阅参考资料