GUI不在框架处显示命令

Question

I programmed a little game in Java for school. We have library with given functions. I write a code that repeats a command (while), i checked with the println that the command is running correctly, but in the GUI you can't see the result, only the last result.

Project: https://drive.google.com/open?id=0B5Ehxz_FAn6BMjVPOWY5MkgycVk&authuser=0

Code:

public void spielen () {
        if (guthaben > 0) {
            if (endlosspielAktiv) {
                while (guthaben > 0) {
                    kasten.Ringe.faerbeUm(); //Here the GUI doesn't show the results
                    ZEICHENFENSTER.gibFenster().warte(500);
                    guthabenRunter();
                }
                setEndlosspielAktiv(false);
            } else {
                kasten.Ringe.faerbeUm();
            }
        } else if (guthaben == 0) {
            setEndlosspielAktiv(false);
        }
        guthabenRunter();
    }

Answer 1

Your GUI is updated only after all your pending and running methods of the calling thread returned. In your case the update of the GUI delays until the method spielen() returned.

To have an immediate result, you could use an additional Thread like this:

public void spielen () {
        new Thread(new Runnable() {

            @Override
            public void run() {
                if (guthaben > 0) {
                    if (endlosspielAktiv) {
                        while (guthaben > 0) {
                            kasten.Ringe.faerbeUm();
                            ZEICHENFENSTER.gibFenster().warte(500);                            
                            guthabenRunter();
                        }
                        setEndlosspielAktiv(false);
                    } else {
                        kasten.Ringe.faerbeUm();
                    }
                } else if (guthaben == 0) {
                    setEndlosspielAktiv(false);
                }
                guthabenRunter();
            }
        }).start();        
    }

All code of spielen() is running asynchronous and doesn't block the method returning.

If you want to know more about threading, i can recommend you reading the according chapter of the (german) E-Book http://openbook.rheinwerk-verlag.de/javainsel9/javainsel_14_003.htm