java - Components in second JFrame not showing up -

i want start jframe pressing button in jframe. if press button shows jframe not buttons , sliders in it.

public class mainmenu extends jframe {   private jframe klick; private static final long serialversionuid = 9002;   public static void main(string[] args) {      new mainmenu();  }   public mainmenu() {     buildgui1();  } public void buildgui1() throws nullpointerexception {     settitle("hauptmenü");           setsize(800, 480);     setlayout(new gridlayout());     setalwaysontop(false);     setlocation((toolkit.getdefaulttoolkit().getscreensize().width)/4, (toolkit.getdefaulttoolkit().getscreensize().height)/4);     setdefaultcloseoperation(jframe.exit_on_close);     setresizable(false);     setvisible(true);     final jbutton startclickbt = new jbutton("start clicker");     startclickbt.addactionlistener(new actionlistener() {         public void actionperformed(actionevent e) {             dispose();             if(klick == null ) {                 klick =new clicker();                 add(klick);             }           }     });      add(startclickbt);       } 

}

the second has quite same costructor.sliders , buttons not static. @ places buttons should appear screen black.

hope can me :)

edit:

public class clicker extends jframe {      private static final long serialversionuid = 9001;     protected jpanel panel;     static click j = null;     protected jslider jsl;     protected jtextfield tf;     static final int cps_min= 0;     static final int cps_max= 100;     static final int cps_init= 25;     private int amount;     private boolean visible;      public int getdelay() {         return math.abs(jsl.getvalue()-100);     }     public int getamount() {         return amount;     }     public boolean getvisible() {         return visible;     }     public void setopen(boolean visible) {         this.visible=visible;     }      public clicker(boolean visible) {          buildgui(visible);         j = new click(false).addposition(new point((toolkit.getdefaulttoolkit().getscreensize().width)/2, (toolkit.getdefaulttoolkit().getscreensize().height)/2)).addposition(new point(getlocation().x+1, getlocation().y+20));         while(true) {              j.runclicks(getdelay());         }     }      public clicker() {         buildgui(true);         j = new click(false).addposition(new point((toolkit.getdefaulttoolkit().getscreensize().width)/2, (toolkit.getdefaulttoolkit().getscreensize().height)/2)).addposition(new point(getlocation().x+1, getlocation().y+20));         while(true) {              j.runclicks(getdelay());         }     }     public void buildgui(boolean visible) {          settitle("clicker");         setsize(340, 200);         setlayout(new gridlayout());         setalwaysontop(true);         setlocation(0, 0);         setdefaultcloseoperation(jframe.exit_on_close);         setresizable(false);         setvisible(visible);          final jbutton bt1 = new jbutton("schließen");         bt1.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e) {                 system.exit(0);             }         });         final jbutton bt2 = new jbutton("start  ");         bt2.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e) {                 j.setclick(true);             }         });         final jbutton bt3 = new jbutton("stop       ");         bt3.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e) {                 j.setclick(false);                 joptionpane.showmessagedialog(null, "klicken gestoppt. klicks: " + j.getclickamount());                 j.setclickamout(0);             }         });         final jbutton bt4 = new jbutton("startanzahl");         bt4.addactionlistener(new actionlistener() {             private int amount;              public void actionperformed(actionevent e) {                 string wert = tf.gettext();                 try {                     amount = integer.parseint(wert);                 }catch(exception ee) {                     joptionpane.showmessagedialog(null,"das war keine zahl oder mehr als ein integer");                 }                  j.doclick(amount);               }         });         tf = new jtextfield("anzahl gewünschte clicks max "+ integer.max_value, 10);         tf.seteditable(true);           jsl = new jslider(jslider.horizontal,cps_min,cps_max,cps_init);         jsl.setminortickspacing(5);         jsl.setmajortickspacing(10);         jsl.setpaintticks(true);         jsl.setpaintlabels(true);          panel = new jpanel();         panel.addmousemotionlistener(new mousemotionlistener() {              @override             public void mousedragged(mouseevent event) {                 j.setclick(false);               }              @override             public void mousemoved(mouseevent event) {                 j.setclick(false);                       }         });          panel.addkeylistener(new keyadapter() {              @override             public void keypressed(keyevent e) {                 if(e.getkeycode() == keyevent.vk_f1) {                     j.setclick(true);                 }                 if(e.getkeycode() == keyevent.vk_f2) {                     j.setclick(false);                 }             }          });           add(panel);         add(bt2);         add(bt3);         add(bt1);         add(bt4);         add(jsl);         add(tf);          pack();     }  } 

make setvisible last thing call...

public void buildgui1() throws nullpointerexception {     settitle("hauptmenü");     setsize(800, 480);     setlayout(new gridlayout());     setalwaysontop(false);     setlocation((toolkit.getdefaulttoolkit().getscreensize().width) / 4, (toolkit.getdefaulttoolkit().getscreensize().height) / 4);     setdefaultcloseoperation(jframe.exit_on_close);     setresizable(false);     final jbutton startclickbt = new jbutton("start clicker");     startclickbt.addactionlistener(new actionlistener() {         public void actionperformed(actionevent e) {             dispose();             if (klick == null) {                 klick = new clicker();                 add(klick);                 // add when need add/remove components                 revalidate();                 repaint();             }          }     });      add(startclickbt);     // move here     setvisible(true);  } 

also, use revalidate() , repaint() encourage container update it's layout when adding new components

recommendations:

• make sure ui started within context of edt, see initial threads more details
• avoid extending directly top level containers jframe , instead consider using jpanel base container. free's ui wider range of use-cases , prevents getting locked in (as can't add frames other frames)
• the use of multiple jframes, good/bad practice?

updated

you have 2 immediate problems

1. clicker extends jframe, trying add container, not possible in swing , cause exception, however...
2. you blocking event dispatching thread while (true) loop, meaning swing unable process new events, including repaint events

for example...

public clicker(boolean visible) {      buildgui(visible);     j = new click(false).addposition(new point((toolkit.getdefaulttoolkit().getscreensize().width) / 2, (toolkit.getdefaulttoolkit().getscreensize().height) / 2)).addposition(new point(getlocation().x + 1, getlocation().y + 20));     // bad     while (true) {          j.runclicks(getdelay());     } }  public clicker() {     buildgui(true);     j = new click(false).addposition(new point((toolkit.getdefaulttoolkit().getscreensize().width) / 2, (toolkit.getdefaulttoolkit().getscreensize().height) / 2)).addposition(new point(getlocation().x + 1, getlocation().y + 20));     // bad     while (true) {          j.runclicks(getdelay());     } } 

now, click looks it's ui component brings bunch of other problems, don't have code it's impossible comment.

the immediate solutions might use a:

• swingworker, see worker threads , swingworker more details

• swing timer, see how use swing timers more details

• plain old thread

things remember

• swing (like ui frameworks) single threaded, blocks thread (like never ending loops), prevent processing new events, including paint events, make application it's "hung", because has
• swing not thread safe. interactions ui must made within context of event dispatching thread. both swingworker , swing timer provide capability update ui safely.