動態增加JTable大小

Question

我有一個總是正方形的矩陣，我製作了一個JTable來顯示它的內容。我需要JTable來調整其行數/列數以匹配矩陣。 我正在使用的方法調整顯示在表上的行數，但列數保持不變。這是爲什麼？那我該怎麼做呢？

下面的代碼缺少與此問題無關的方法。矩陣正在更新，因爲它應該是，我檢查。

public class SomeClass{ 

    TableModel tableModel = new AbstractTableModel() { 
       public int getColumnCount() { 
        return matrix.lines.size()+1; 
       } 

       public int getRowCount() { 
        return matrix.lines.size()+1; 
       } 

       public Object getValueAt(int row, int col) { 
        Object val = "+"; 

        if(row == 0 && col == 0) 
         return " "; 

        if(row == 0) { 
         try { 
          val = matrix.lines.get(0).cells.get(col-1).nodeId; 
         } catch (Exception e){ 
          val = "-"; 
         } 
         return val; 
        } 

        if(col == 0) { 
         try { 
          val = matrix.lines.get(row-1).nodeId; 
         } catch (Exception e){ 
          val = "-"; 
         } 
         return val; 
        } 


        try { 
         val = (int)observer.nodeList.get(id).matrix.lines.get(row-1).cells.get(col-1).dist; 
        } catch (Exception e){ 
         val = "-"; 
        } 

        return val; 
       } 

      }; 


    public void updateTable(){ 
     //STUFF HERE 
    } 
} 

updateTable方法在矩陣更新後調用。我已經嘗試了幾種這種方法的實現，結果如下所示。

實現1

public void updateTable(){ 
     ((AbstractTableModel) table.table.getModel()).fireTableDataChanged(); 
    } 

結果：行數被更新，但列數保持不變。

實現2

public void updateTable(){ 
     ((AbstractTableModel) table.table.getModel()).fireTableStructureChanged(); 
    } 

結果：工程，大部分的時間...這兩個方面的更新，但一個例外是偶爾拋出：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 1 >= 1 
at java.util.Vector.elementAt(Vector.java:474) 
at javax.swing.table.DefaultTableColumnModel.getColumn(DefaultTableColumnModel.java:294) 
at javax.swing.plaf.basic.BasicTableUI.paintCells(BasicTableUI.java:2012) 
at javax.swing.plaf.basic.BasicTableUI.paint(BasicTableUI.java:1812) 
at javax.swing.plaf.ComponentUI.update(ComponentUI.java:161) 
at javax.swing.JComponent.paintComponent(JComponent.java:780) 
at javax.swing.JComponent.paint(JComponent.java:1056) 
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) 

Answer 1

當您創建一個自定義TableModel延伸AbstractTableModel你有責任發射正確的TableModel事件（reference）。

這意味着當您的matrix通過添加/刪除列進行更改時，應該調用fireTableStructureChanged（從AbstractTableModel子類中）。

如果JTable的autoCreateColumnsFromModel屬性爲true，則JTable將放棄其擁有的任何表列，並按它們在模型中出現的順序重新分配缺省列。

這意味着，你的updateTable方法應爲：

public void updateTable() 
{ 
    fireTableStructureChanged(); 
}