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Thread: JInternalFrame Only Show one Window

  1. #1
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    Default JInternalFrame Only Show one Window

    Window1 is JInternalFrame
    I want when the menu item is clicked, the JInternalFrame only can show one window, if we click the menu item again, i will detect that JInternalFrame is exist, how to do that?

    Here is my code :
        private void jMenuItem1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
            // TODO add your handling code here:
            Window1 frm1 = new Window1();
            if (frm1.isShowing()) {
                JOptionPane.showMessageDialog(null, "yo");
            } else {
                desktopPane.add(frm1);
                frm1.show();
            }
        }

    it still showing new Window everytime i click the menu item


  2. #2
    Super Moderator jps's Avatar
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    Default Re: JInternalFrame Only Show one Window

    Quote Originally Posted by sadaharu View Post
    it still showing new Window everytime i click the menu item
    That is what the code says to do. thing t = new thing;
    if you don't want a new one each time don't make a new one each time, keep a reference to the old one

  3. #3
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    Default Re: JInternalFrame Only Show one Window

    Quote Originally Posted by jps View Post
    That is what the code says to do. thing t = new thing;
    if you don't want a new one each time don't make a new one each time, keep a reference to the old one
    how to keep it as it old one dude?

  4. #4
    Super Moderator jps's Avatar
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    Default Re: JInternalFrame Only Show one Window

    In the posted method, frm1 is declared as a local variable. (Defined within the scope of the method)

    Any variable created within a method is garbage when the method returns. (Either by hitting a return statement or reaching the } closing the method)

    Declare the variable as a class variable. Check the link and post any questions you may have left

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