程序窗口不显示在框架中

Question

I have a program that has a login window, a register window and a program window. When I run the program the login window pops up first and everything is good. I click register and that window pops up and everything is good, but when I click login, the program window will open but nothing will show in the frame. I have all my components stored in a JTabbedPane and I store the JTabbedPane in a JPanel so that I can use it in the JFrame, but when I open the program window it shows a blank frame. The only thing is if you hover over a position where a textField is, it will show the text cursor and if you click it will bring up the text field! How do I get it to show all the components in the panel when the window opens?

public JPanel panelProgram()
{
    programPanel.setLayout(null);

    tabbedPane = new JTabbedPane();
    tabbedPane.setBounds(0, 10, programW - 10, programH - 10);
    tabbedPane.setVisible(true);
    ImageIcon icon = new ImageIcon("src/cpt/admin/images/middle.gif");

    proPanTab1 = showInputScreen();
    tabbedPane.addTab("Input Accounts", icon, proPanTab1, "Input New Acocunts");

    proPanTab2 = showSearchScreen();
    tabbedPane.addTab("Search Accounts", icon, proPanTab2, "Search Through Accounts");

    proPanTab3 = showEmailScreen();
    tabbedPane.addTab("Send Email", icon, proPanTab3, "Send an Email to Accounts");

    tabbedPane.setTabLayoutPolicy(JTabbedPane.WRAP_TAB_LAYOUT);

    programPanel.add(tabbedPane);

    return programPanel;
}

Answer 1

Using programPanel.setLayout(null); will set the components in that panel to zero and thus will not show. You can get the size of the components by calling getPreferredSize() .

You should use a LayoutManager for better layout alternatives.