Question

I'm building a simple Swing chat interface (I did it on JavaFX and it was quite easy) but something is going wrong and I don't understand why. Can anyone help?

From main class, I create a new ChatUI, like this:

public static void main(String[] args) {

    EventQueue.invokeLater(new Runnable() {
        public void run() {
           chatFrame = new ChatUI();
            UIHelper.chatFrameInit(); 

        }
     });
}

From the UIHelper class, I can easily set up my frame, like this:

public class UIHelper {
public static void chatFrameInit() {
    chatFrame.setTitle("Your Chat");
    chatFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    chatFrame.setVisible(true);
}

}

In order to append a text string to the textArea, i've created a public method into the ChatUI class:

public ChatUI() {
    initComponents();
}

public void addChat(String t) {
    jTextArea1.append(t);
}

...

// Variables declaration - do not modify                     
private javax.swing.JScrollPane jScrollPane2;
public javax.swing.JTextArea jTextArea1;
// End of variables declaration

}

The problem is that, if I try to refer to this method (and any other public methods and fields into the ChatUI class), I receive a "Cannot find symbol" error.

Updating a Swing jtextArea from outside the class

0 个答案: