爪哇连续图像绘制在同时循环切换案例

我是新来的java和我正在工作的音乐键盘的用户界面的一部分，将按键时显示在音乐工作人员的音乐笔记。我想我会在一个while循环内使用我的PC的键盘和开关盒来测试这个。我希望它在按下某个键时连续绘制笔记并将它们正确分隔。每当我尝试下面的代码时，程序都会绘制第一个注释并列出一长串错误。我很确定重绘在这种情况下不是正确的做法，但我似乎已经碰壁了。爪哇连续图像绘制在同时循环切换案例

我当前的代码是在这里：

public static void keyNoteTest() 
{ 
    int count = 0; 
    int nx = 175; 
    boolean quit = false; 

    JFrame frame = new JFrame(); 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

    JPanel panel = (JPanel) frame.getContentPane(); 
    panel.setLayout(null); 
    panel.setBackground(Color.white); 

    frame.setSize(800, 480); 
    frame.setVisible(true); 

    ImageIcon musicStaff = new ImageIcon("UI Graphics/trebleClef.jpg"); 
    JLabel mSL = new JLabel(musicStaff); 
    panel.add(mSL); 
    Dimension mSize = mSL.getPreferredSize(); 
    int msx = 75, msy = 117; 
    mSL.setBounds(msx, msy, mSize.width, mSize.height); 

    ImageIcon testNote = new ImageIcon("UI Graphics/quarter_note.jpg"); 
    JLabel tN = new JLabel(testNote); 
    Dimension size = tN.getPreferredSize(); 

    Scanner keyboard = new Scanner(System.in); 
    char c = keyboard.next().charAt(0); 

    while(quit != true) 
    { 
     switch(c) 
     { 
      case 'e': 
       panel.add(tN); 
       tN.setBounds(nx, 230, size.width, size.height); 
       break; 
      case 'g': 
       panel.add(tN); 
       tN.setBounds(nx, 215, size.width, size.height); 
       break; 
      case 'b': 
       panel.add(tN); 
       tN.setBounds(nx, 200, size.width, size.height); 
       break; 
      case 'd': 
       panel.add(tN); 
       tN.setBounds(nx, 185, size.width, size.height); 
       break; 
      case 'f': 
       panel.add(tN); 
       tN.setBounds(nx, 170, size.width, size.height); 
       break; 
      case 'v': 
       panel.add(tN); 
       tN.setBounds(nx, 223, size.width, size.height); 
       break; 
      case 'a': 
       panel.add(tN); 
       tN.setBounds(nx, 207, size.width, size.height); 
       break; 
      case 'c': 
       panel.add(tN); 
       tN.setBounds(nx, 193, size.width, size.height); 
       break; 
      case 'r': 
       panel.add(tN); 
       tN.setBounds(nx, 177, size.width, size.height); 
       break; 
      default: 
       break; 
     } 
     nx = nx + 50; 
     count = count + 1; 
     panel.repaint(); 
    } 
}

在运行时，我输入“A”到控制台和音符显示。然后，NetBeans输出：

run: 
a 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 1 
    at java.awt.Container.getComponent(Container.java:334) 
    at javax.swing.JComponent.rectangleIsObscured(JComponent.java:4390) 
    at javax.swing.JComponent.paint(JComponent.java:1054) 
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210) 
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579) 
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502) 
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272) 
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158) 
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:831) 
    at javax.swing.RepaintManager$4.run(RepaintManager.java:814) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) 
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789) 
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738) 
    at javax.swing.RepaintManager.access$1200(RepaintManager.java:64) 
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732) 
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 
BUILD SUCCESSFUL (total time: 6 seconds)

谢谢。

来源

2016-12-01 JMV12

请告诉我们堆栈跟踪 – ItamarG3

目前试图找到这种照顾。不适用于NetBeans。我道歉。 – JMV12

错误说你试图访问一个不存在的组件getComponent - 我们需要那部分代码，最好是一个完整的运行程序 – gpasch

您不能在GUI应用程序中使用键盘扫描仪。这似乎有效，但你肯定会遇到无数的问题。

相反，您需要设置适当的GUI，并让它运行其事件循环。正是如何做到这一点取决于你正在使用的特定的GUI框架。无论如何，我确信interwebz会充满示范代码，向您展示如何设置事件循环。它应该只是几行代码。

在这个图形用户界面中，您将创建一个控件，该控件将具有焦点，以便它接收键盘事件。

因此，GUI将调用您的事件观察者来通知您已按下某个键。

然后，你的关键事件的观察者会做它的东西，然后GUI将采取重新粉刷等

来源

2016-12-01 19:42:55

你正在描述一种替代方法，但你没有解决用户的问题，我们得到了很多那些 - 我确信我有一个理论，为什么量子移动 – gpasch

@gpasch以非常错误的方式使用某些东西，而且你肯定会得到很难解释的奇怪行为。不仅我不愿意排查这种非常错误的用法是如何导致这种确切的行为的，而且也不会对OP有任何帮助，因为他最好不要这样做，而且没有其他人会这样做在将来阅读这个答案有什么可以从这样的解释中获益。阅读任何家庭用品的说明：***不当使用会导致保修无效*** –

另外，我没有描述*替代*方法，我正在描述*方法。 –

爪哇连续图像绘制在同时循环切换案例

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