在jbutton上打开JFrame窗口

Question

我在点击时打开新的jframe窗口时出现问题。 我认为我做得对，但我不确定。 在动作监听器中（在下面列出的第一类中）

testing2 test = new testing2();
                testing2.setVisible(true);

但是testing2.setVisible（true）说 ＆＃34;无法从类型JComponent＆＃34;中对非静态方法setVisible（boolean）进行静态引用。 任何帮助表示赞赏。

import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;

    /*************************************************************
         *  TextPanel Class (with main method)
     *************************************************************/

    class testing2 extends JPanel {
        public testing2() {

            JButton btnTesting = new JButton("Testing 2");
            add(btnTesting);
        }
      // override the paintComponent method
      // THE MAIN DEMO OF THIS EXAMPLE:

      public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Font f = new Font("SansSerif", Font.BOLD, 14);
        Font fi = new Font("SansSerif", Font.BOLD + Font.ITALIC, 14);
        FontMetrics fm = g.getFontMetrics(f);
        FontMetrics fim = g.getFontMetrics(fi);
        int cx = 75; int cy = 100;
        g.setFont(f);
        g.drawString("Hello, ", cx, cy);
        cx += fm.stringWidth("Hello, ");
        g.setFont(fi);
        g.drawString("World!", cx, cy);
      } //paintComponent

      //=============================================
      ///////////// main ////////////////////////////

      public static void main(String[] args) {
        JFrame f = new MyFrame("My Hello World Frame");
        f.show();
      } //main

    } //class TextPanel

    /*************************************************************
            MyFrame Class
     *************************************************************/

    class MyFrame extends JFrame {
      public MyFrame(String s) {
        // Frame Parameters
        setTitle(s);
        setSize(300,200); // default size is 0,0
        setLocation(10,200); // default is 0,0 (top left corner)

        // Window Listeners
        addWindowListener(new WindowAdapter() {
          public void windowClosing(WindowEvent e) {
            System.exit(0);
          } //windowClosing
        }); //addWindowLister

        // Add Panels
        Container contentPane = getContentPane();
        contentPane.add(new testing());

      } //constructor MyFrame
    } //class MyFrame

import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;

    /*************************************************************
         *  TextPanel Class (with main method)
     *************************************************************/

    class testing extends JPanel {
        public testing() {

            JButton btnTesting = new JButton("Testing 2");
            btnTesting.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {

                }
            });
            add(btnTesting);
        }
      // override the paintComponent method
      // THE MAIN DEMO OF THIS EXAMPLE:

      public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Font f = new Font("SansSerif", Font.BOLD, 14);
        Font fi = new Font("SansSerif", Font.BOLD + Font.ITALIC, 14);
        FontMetrics fm = g.getFontMetrics(f);
        FontMetrics fim = g.getFontMetrics(fi);
        int cx = 75; int cy = 100;
        g.setFont(f);
        g.drawString("Hello, ", cx, cy);
        cx += fm.stringWidth("Hello, ");
        g.setFont(fi);
        g.drawString("World!", cx, cy);
      } //paintComponent

      //=============================================
      ///////////// main ////////////////////////////

      public static void main(String[] args) {
        JFrame f = new MyFrame("My Hello World Frame");
        f.show();
      } //main

    } //class TextPanel

    /*************************************************************
            MyFrame Class
     *************************************************************/

    class MyFrame extends JFrame {
      public MyFrame(String s) {
        // Frame Parameters
        setTitle(s);
        setSize(300,200); // default size is 0,0
        setLocation(10,200); // default is 0,0 (top left corner)

        System.err.println("Here");
        testing2 test = new testing2();
        test.setVisible(true);


        // Window Listeners
        addWindowListener(new WindowAdapter() {
          public void windowClosing(WindowEvent e) {
            System.exit(0);
          } //windowClosing
        }); //addWindowLister

        // Add Panels
        Container contentPane = getContentPane();
        contentPane.add(new testing());

      } //constructor MyFrame
    } //class MyFrame

Answer 1

使用测试，而不是测试2

            test.setVisible(true); //was testing2.setVisible(true);