FocusListener上可編輯JCombobox沒有射擊

Question

首先： 對不起，我無法提供SSCCE。我試圖在一個小項目上重新創建這個問題，但沒有成功，或者我應該說成功，因爲它在那裏工作！

所以這裏是我的問題： 我有一個可編輯的JCombobox，它應該通過單擊編輯器組件來監聽焦點事件。但它不是。

下面的代碼片段，我裝上監聽器：

cmbZoom.setToolTipText(locale.getString("GUI_ZoomFactor")); 
cmbZoom.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16)); 
cmbZoom.setPreferredSize(new Dimension(88, 29)); 
cmbZoom.setEditable(true); 
((JTextField)cmbZoom.getEditor().getEditorComponent()).setHorizontalAlignment(JTextField.CENTER); 
cmbZoom.getEditor().getEditorComponent().addFocusListener(
    new FocusListener(){ 
    public void focusGained(FocusEvent arg0) { 
     System.out.println("GAINED"); 
    } 

    public void focusLost(FocusEvent arg0) { 
     System.out.println("LOST"); 
    } 
    }); 

我已經嘗試去除所有其他的監聽器組合框，去掉觀察者模式，使受保護的組合框，並貼在每個聽者孩子，...

我也試圖重新實現它像寫這篇文章： JCombobox focusLost is not firing-why is that?

是否有調試事件的好辦法？

整個項目可以在Github上查看： https://github.com/nexxx/Database-Analyzer

工具欄類可以在這裏找到（開始於第98行代碼）： https://github.com/nexxx/Database-Analyzer/blob/master/src/dba/gui/auxClasses/toolBars/ToolBar.java

Answer 1

相同的代碼會導致他人在某些情況下的問題，但沒有使我懷疑你的代碼可能無法在AWT event dispatch thread被執行的事實。

Answer 2

• 我倒是建議不要與Item & DocumentListenerFocusListener混合加入到JComboBox'es Editor，可以創建無限循環

˚F或者例如，

import java.awt.*; 
import java.awt.event.FocusEvent; 
import java.awt.event.FocusListener; 
import java.util.Vector; 
import javax.swing.*; 
import javax.swing.UIManager; 
import javax.swing.plaf.ColorUIResource; 
import javax.swing.plaf.metal.MetalComboBoxButton; 

public class MyComboBox { 

    private Vector<String> listSomeString = new Vector<String>(); 
    private JComboBox someComboBox = new JComboBox(listSomeString); 
    private JComboBox editableComboBox = new JComboBox(listSomeString); 
    private JComboBox non_EditableComboBox = new JComboBox(listSomeString); 
    private JFrame frame; 

    public MyComboBox() { 
     listSomeString.add("-"); 
     listSomeString.add("Snowboarding"); 
     listSomeString.add("Rowing"); 
     listSomeString.add("Knitting"); 
     listSomeString.add("Speed reading"); 
// 
     someComboBox.setPrototypeDisplayValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"); 
     someComboBox.setFont(new Font("Serif", Font.BOLD, 16)); 
     someComboBox.setEditable(true); 
     someComboBox.getEditor().getEditorComponent().setBackground(Color.YELLOW); 
     ((JTextField) someComboBox.getEditor().getEditorComponent()).setBackground(Color.YELLOW); 
     someComboBox.getEditor().getEditorComponent().addFocusListener(fcsListener); 
// 
     editableComboBox.setPrototypeDisplayValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"); 
     editableComboBox.setFont(new Font("Serif", Font.BOLD, 16)); 
     editableComboBox.setEditable(true); 
     JTextField text = ((JTextField) editableComboBox.getEditor().getEditorComponent()); 
     text.setBackground(Color.YELLOW); 
     JComboBox coloredArrowsCombo = editableComboBox; 
     Component[] comp = coloredArrowsCombo.getComponents(); 
     for (int i = 0; i < comp.length; i++) { 
      if (comp[i] instanceof MetalComboBoxButton) { 
       MetalComboBoxButton coloredArrowsButton = (MetalComboBoxButton) comp[i]; 
       coloredArrowsButton.setBackground(null); 
       break; 
      } 
     } 
     editableComboBox.getEditor().getEditorComponent().addFocusListener(fcsListener); 
// 
     non_EditableComboBox.setPrototypeDisplayValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"); 
     non_EditableComboBox.setFont(new Font("Serif", Font.BOLD, 16)); 
     non_EditableComboBox.addFocusListener(fcsListener); 
// 
     frame = new JFrame(); 
     frame.setLayout(new GridLayout(0, 1, 10, 10)); 
     frame.add(someComboBox); 
     frame.add(editableComboBox); 
     frame.add(non_EditableComboBox); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setLocation(100, 100); 
     frame.pack(); 
     frame.setVisible(true); 
    } 

    // 
    private FocusListener fcsListener = new FocusListener() { 

     @Override 
     public void focusGained(FocusEvent e) { 
      dumpInfo(e); 
     } 

     @Override 
     public void focusLost(FocusEvent e) { 
      dumpInfo(e); 
     } 

     private void dumpInfo(FocusEvent e) { 
      final Component c = e.getComponent(); 
      System.out.println("Source : " + name(e.getComponent())); 
      System.out.println("Opposite : " + name(e.getOppositeComponent())); 
      System.out.println("Temporary: " + e.isTemporary()); 
      if (c instanceof JFormattedTextField) {//works for editable JComboBox too 
       SwingUtilities.invokeLater(new Runnable() { 

        @Override 
        public void run() { 
         ((JFormattedTextField) c).selectAll(); 
        } 
       }); 
      } else if (c instanceof JTextField) { 
       SwingUtilities.invokeLater(new Runnable() { 

        @Override 
        public void run() { 
         ((JTextField) c).selectAll(); 
        } 
       }); 
      } else if (c instanceof JTextField) { 
       SwingUtilities.invokeLater(new Runnable() { 

        @Override 
        public void run() { 
         ((JComboBox) c).getEditor().selectAll(); 
        } 
       }); 
      } 
     } 

     private String name(Component c) { 
      return (c == null) ? null : c.getName(); 
     } 
    }; 

    public static void main(String[] args) { 
     UIManager.put("ComboBox.background", new ColorUIResource(Color.yellow)); 
     UIManager.put("JTextField.background", new ColorUIResource(Color.yellow)); 
     UIManager.put("ComboBox.selectionBackground", new ColorUIResource(Color.magenta)); 
     UIManager.put("ComboBox.selectionForeground", new ColorUIResource(Color.blue)); 
     SwingUtilities.invokeLater(new Runnable() { 

      @Override 
      public void run() { 
       MyComboBox aCTF = new MyComboBox(); 
      } 
     }); 
    } 
}