jcombobox 作为单元格编辑器 java.awt.IllegalComponentStateException：组件必须显示在屏幕上才能确定其位置

我使用自定义 JComboBox 作为 JTable 中的单元格编辑器。当用户使用键盘控件进入单元格时，它会尝试打开弹出窗口。这会导致以下错误：

java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location
    at java.awt.Component.getLocationOnScreen_NoTreeLock(Component.java:1964)
    at java.awt.Component.getLocationOnScreen(Component.java:1938)
    at javax.swing.JPopupMenu.show(JPopupMenu.java:887)
    at javax.swing.plaf.basic.BasicComboPopup.show(BasicComboPopup.java:191)
    at javax.swing.plaf.basic.BasicComboBoxUI.setPopupVisible(BasicComboBoxUI.java:859)
    at javax.swing.JComboBox.setPopupVisible(JComboBox.java:796)

我看到一些文章说这是一个已知问题，解决方案是设置：

    comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);

然而这并没有帮助。无论如何，这应该做什么？

我读过的所有有关此问题的帖子和文章对于问题的本质都非常模糊。

有谁了解这个问题发生的本质？我的组合框是非常自定义的，因此它将有助于理解问题的基础，以便我可以修复代码。

这是在捕获并调用 setPopupVisible(true) 的组合框上获得焦点事件时触发的；

 public void focusGained(java.awt.event.FocusEvent e)
 {
        //if focus is gained then make sure we show the popup if it is suppose to be visible
            setPopupVisible(true);
        //and highlight the selected text if any
        comboTextEditor.setCaretPosition(comboTextEditor.getText().length());
        comboTextEditor.moveCaretPosition(0);
 }

顺便说一句，我在 Java 1.7_40 中得到与 Java 1.6_45 相同的结果

完整的堆栈跟踪：

Exception in thread "AWT-EventQueue-1" java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location
    at java.awt.Component.getLocationOnScreen_NoTreeLock(Component.java:1964)
    at java.awt.Component.getLocationOnScreen(Component.java:1938)
    at javax.swing.JPopupMenu.show(JPopupMenu.java:887)
    at javax.swing.plaf.basic.BasicComboPopup.show(BasicComboPopup.java:191)
    at javax.swing.plaf.basic.BasicComboBoxUI.setPopupVisible(BasicComboBoxUI.java:859)
    at javax.swing.JComboBox.setPopupVisible(JComboBox.java:796)
    at com.mbs.generic.view.swing.combobox.AutoCompleteComboBox$1.focusGained(AutoCompleteComboBox.java:185)
    at java.awt.AWTEventMulticaster.focusGained(AWTEventMulticaster.java:203)
    at java.awt.Component.processFocusEvent(Component.java:6179)
    at java.awt.Component.processEvent(Component.java:6046)
    at java.awt.Container.processEvent(Container.java:2039)
    at java.awt.Component.dispatchEventImpl(Component.java:4653)
    at java.awt.Container.dispatchEventImpl(Container.java:2097)
    at java.awt.Component.dispatchEvent(Component.java:4481)
    at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
    at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:901)
    at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:513)
    at java.awt.Component.dispatchEventImpl(Component.java:4525)
    at java.awt.Container.dispatchEventImpl(Container.java:2097)
    at java.awt.Component.dispatchEvent(Component.java:4481)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:648)
    at java.awt.EventQueue.access$000(EventQueue.java:84)
    at java.awt.EventQueue$1.run(EventQueue.java:607)
    at java.awt.EventQueue$1.run(EventQueue.java:605)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
    at java.awt.EventQueue$2.run(EventQueue.java:621)
    at java.awt.EventQueue$2.run(EventQueue.java:619)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:618)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

thanks

首先，让我解释一下什么comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);做。通常，将鼠标悬停在某个项目上或按键盘上的箭头键将导致选择该项目上的项目JComboBox立即地。自评选活动以来JComboBox将导致单元格编辑过程停止，此行为不适合表格单元格。因此，当设置此特殊客户端属性时，项目将在弹出列表中显示为选中状态，但不会在JComboBox然而。只有提交的项目（通过单击或 Enter 键）才会更改在JComboBox导致编辑结束。至少，这适用于BasicLookAndFeel及其衍生物。

你遇到的问题完全不同。正如异常消息和堆栈跟踪清楚地表明的那样，外观尝试打开JPopupMenu与相关的JComboBox（按照您的要求）但它无法确定弹出菜单在屏幕上的位置，因为您的JComboBox不是屏幕上显示的镜头。它想要的位置的原因JComboBox是它打开相对于JComboBox.

剩下的问题是为什么您收到focusGained from a JComboBox这没有显示在屏幕上（或者为什么你认为你这样做了）。