【问题标题】:java swing components don't show inside paneljava swing组件不显示在面板内
【发布时间】:2013-05-21 15:53:07
【问题描述】:

我对挥杆还很陌生,所以我相信这可能很简单。希望你们中的一些人能帮我一把。 这是一个更复杂场景的一部分,但我设法把它放在一个简单的例子中。

我正在使用 Netbeans,我正在尝试创建一个框架,其中包含一个带有一些复选框的面板(由框架动态添加)。

如果我使用可视化编辑器来创建包含原生组件的整个结构,效果会很好,但问题是我需要一个自定义面板,而这就是它中断的地方。

当我执行应用程序时,我只看到一个没有内容的空白框。

代码如下

框架:

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package contacorrente;

import java.util.HashSet;
import java.util.Set;
import javax.swing.JButton;
import javax.swing.JCheckBox;

/**
 *
 * @author afsilva
 */
public class Test extends javax.swing.JFrame {

    /**
     * Creates new form Test
     */
    public Test() {
        initComponents();
        this.testPanel1.add(new JCheckBox("ergcdf"));
        this.testPanel1.add(new JCheckBox("ergcdf1"));
        this.testPanel1.add(new JCheckBox("ergcdf2"));
        this.testPanel1.add(new JCheckBox("ergcdf3"));
        this.testPanel1.add(new JCheckBox("ergcdf4"));
        this.testPanel1.validate();
        this.validate();
    }

    /**
     * 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() {

        testPanel1 = new contacorrente.TestPanel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setBackground(new java.awt.Color(51, 204, 255));

        testPanel1.setBackground(new java.awt.Color(255, 51, 204));
        testPanel1.setName("testPanel1"); // NOI18N

        javax.swing.GroupLayout testPanel1Layout = new javax.swing.GroupLayout(testPanel1);
        testPanel1.setLayout(testPanel1Layout);
        testPanel1Layout.setHorizontalGroup(
            testPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        testPanel1Layout.setVerticalGroup(
            testPanel1Layout.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)
            .addComponent(testPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(testPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );

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

    /**
     * @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(Test.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Test.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Test.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Test.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 Test().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private contacorrente.TestPanel testPanel1;
    // End of variables declaration
}

我不会粘贴面板代码,因为它只是一个空面板(没有自定义代码)

请帮忙..

提前致谢

【问题讨论】:

    标签: java swing components show


    【解决方案1】:

    您的JCheckBoxes 大小为0,0

    您需要为JCheckBoxes 设置大小

    您的示例没有显示任何内容,但是如果您将构造函数更改为:

    public Test() {
        initComponents();
        JCheckBox x = new JCheckBox("ergcdf"); //create the component,
        x.setSize(100,30);                     //size the component 
        this.testPanel1.add(x);                //and then add it to the panel
        this.testPanel1.add(new JCheckBox("ergcdf1"));
        this.testPanel1.add(new JCheckBox("ergcdf2"));
        this.testPanel1.add(new JCheckBox("ergcdf3"));
        this.testPanel1.add(new JCheckBox("ergcdf4"));
        this.testPanel1.validate();
        this.validate();
    }
    

    它将显示第一个复选框。如果您为每个复选框设置大小,您将看到所有复选框

    【讨论】:

    • 你完全正确!这种行为很奇怪,组件的默认大小不应该为零!?
    • @cattox 不,默认组件大小是0,0,如果你想看到它们你需要设置它们的大小
    【解决方案2】:

    查看以下内容,它可以工作。我不完全确定您缺少什么,因为您的做法有所不同,但是您可以查看它。我在想的是你没有正确声明组件。如果您还没有,我会建议 Netbeans IDE 做摇摆。 (Netbeans.org)

    /*
     * To change this template, choose Tools | Templates
     * and open the template in the editor.
     */
    package swingtest;
    
    /**
     *
     * @author 
     */
    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">                          
        private void initComponents() {
    
            jPanel1 = new javax.swing.JPanel();
            jCheckBox1 = new javax.swing.JCheckBox();
            jCheckBox2 = new javax.swing.JCheckBox();
            jCheckBox3 = new javax.swing.JCheckBox();
            jCheckBox4 = new javax.swing.JCheckBox();
            jCheckBox5 = new javax.swing.JCheckBox();
    
            setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    
            jCheckBox1.setText("ergcdf");
    
            jCheckBox2.setText("ergcdf1");
    
            jCheckBox3.setText("ergcdf2");
    
            jCheckBox4.setText("ergcdf3");
    
            jCheckBox5.setText("ergcdf4");
    
            javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
            jPanel1.setLayout(jPanel1Layout);
            jPanel1Layout.setHorizontalGroup(
                jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addContainerGap()
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                .addComponent(jCheckBox1)
                                .addComponent(jCheckBox2))
                            .addGap(18, 18, 18)
                            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                .addComponent(jCheckBox4)
                                .addComponent(jCheckBox3)))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGap(38, 38, 38)
                            .addComponent(jCheckBox5)))
                    .addContainerGap(250, Short.MAX_VALUE))
            );
            jPanel1Layout.setVerticalGroup(
                jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addContainerGap()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(jCheckBox1)
                        .addComponent(jCheckBox3))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(jCheckBox2)
                        .addComponent(jCheckBox4))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jCheckBox5)
                    .addContainerGap(221, Short.MAX_VALUE))
            );
    
            javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
            getContentPane().setLayout(layout);
            layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(jPanel1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            );
            layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            );
    
            pack();
        }// </editor-fold>                        
    
        /**
         * @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);
                }
            });
        }
        // Variables declaration - do not modify                     
        private javax.swing.JCheckBox jCheckBox1;
        private javax.swing.JCheckBox jCheckBox2;
        private javax.swing.JCheckBox jCheckBox3;
        private javax.swing.JCheckBox jCheckBox4;
        private javax.swing.JCheckBox jCheckBox5;
        private javax.swing.JPanel jPanel1;
        // End of variables declaration                   
    }
    

    【讨论】:

      猜你喜欢
      • 2021-12-26
      • 2012-11-05
      • 1970-01-01
      • 1970-01-01
      • 1970-01-01
      • 1970-01-01
      • 2011-11-16
      • 2010-10-25
      • 1970-01-01
      相关资源
      最近更新 更多