单元格合并

JTABLE单元格合并(转)

最近，我为了做一个管理系统，需要用到合并JTable的单元格。查找了很多资料，终于简单的实现了。现在把代码共享出来，希望对大家有用。

本程序主要实现行的合并，列的合并大家可以根据下面的代码修改。

CMap.java :

package com;

public interface CMap {
/**
* @param row
* logical cell row
* @param column
* logical cell column
* @return number of columns spanned a cell
*/
int span(int row, int column);

/**
* @param row
* logical cell row
* @param column
* logical cell column
* @return the index of a visible cell covering a logical cell
*/
int visibleCell(int row, int column);
}

CTUI.java :

package com;

import javax.swing.table.*;
import javax.swing.plaf.basic.*;
import java.awt.*;
import javax.swing.*;

public class CTUI extends BasicTableUI {
public void paint(Graphics g, JComponent c) {
    Rectangle r = g.getClipBounds();
// int firstRow = table.rowAtPoint(new Point(0, r.y));//JTable table=super.table就好理解
// int lastRow = table.rowAtPoint(new Point(0, r.y + r.height));
    int firstCol = table.columnAtPoint( new Point( r.x , 0 ) );
    int lastCol = table.columnAtPoint(new Point( r.x + r.width, 0 ));
// -1 is a flag that the ending point is outside the table
// if (lastRow < 0)
// lastRow = table.getRowCount() - 1;
   if (lastCol < 0)
    lastCol = table.getColumnCount() - 1;
    for (int i = firstCol; i <= lastCol; i++)
            paintCol(i, g);
} 
private void paintCol(int col, Graphics g) {
  Rectangle r = g.getClipBounds();
  for (int i = 0; i < table.getRowCount(); i++) {
     Rectangle r1 = table.getCellRect( i, col, true);
       if (r1.intersects(r)) // at least a part is visible{
        int sk = ((CTable) table).map.visibleCell( i, col );
        paintCell( sk, col, g, r1);
// increment the column counter
       i += ((CTable) table).map.span( sk, col ) - 1;
      }
  }
}

private void paintCell(int row, int column, Graphics g, Rectangle area) {
      int verticalMargin = table.getRowMargin();
      int horizontalMargin = table.getColumnModel().getColumnMargin();

     Color c = g.getColor();
    g.setColor(table.getGridColor());
    g.drawRect(area.x, area.y, area.width - 1, area.height - 1);
    g.setColor(c);

     if (table.isEditing() && table.getEditingRow() == row&& table.getEditingColumn() == column) {
              Component component = table.getEditorComponent();
                  component.setBounds(area);
                  component.validate();
        } else {
                TableCellRenderer renderer = table.getCellRenderer(row, column);
                Component component = table.prepareRenderer(renderer, row, column);
        if (component.getParent() == null)
          rendererPane.add(component);
         rendererPane.paintComponent(g, component, table, area.x, area.y, area.width, area.height, true);
                  }
          }
}

CTable.java :

public class CTable extends JTable {
  public CMap map;

  public CTable(CMap cmp, TableModel tbl) {
     super(tbl);
    map = cmp;
    setUI(new CTUI());
  }

public Rectangle getCellRect(int row, int column, boolean includeSpacing) {
// required because getCellRect is used in JTable constructor
     if (map == null)
    return super.getCellRect(row, column, includeSpacing);
// add widths of all spanned logical cells
     int sk = map.visibleCell(row, column);
//Rectangle r1 = super.getCellRect(row, sk, includeSpacing);
     Rectangle r1 = super.getCellRect( sk, column, includeSpacing);
        if (map.span( sk, column ) != 1)
           for (int i = 1; i < map.span( sk, column ); i++) {
//r1.width += getColumnModel().getColumn(sk + i).getWidth();
           r1.height += this.getRowHeight( sk + i );
}
return r1;
}
public int rowAtPoint(Point p) {
    int x = super.columnAtPoint(p);
// -1 is returned by columnAtPoint if the point is not in the table
      if (x < 0)
           return x;
    int y = super.rowAtPoint(p);
         return map.visibleCell(y, x);
     }
}

CMap1.java :

/******************************************************************************************

CMap1对CMap地实现

span( ) 表示合并的单元格的列，返回的是合并的格数。

visibleCell() 表示要渲染的格。返回的渲染的开始格的行。

本程序的table是16行10列，合并的单元格是第一列和最后一列（最后一列是第10列）每两个行。

*******************************************************************************************/

package com;

import javax.swing.*;
import javax.swing.table.*;

class CMap1 implements CMap {
public int span(int row, int column) {
   if( column == 0 || column == 9 )
   return 2;
   return 1;
 }

下面的程序进行测试。

package com;

import javax.swing.*;
import javax.swing.table.*;

public class CTest {
public static void main(String args[]) {
JFrame jf = new JFrame("Table with cell spanning");

CMap m = new CMap1();
DefaultTableModel tm = new DefaultTableModel( 16, 10 ){
  public boolean isCellEditable( int indexRow, int indexColumn )
                 {return false;}
               };
//tm.isCellEditable( 16, 10 );
 tm.setValueAt( "port1", 0, 0);//对一个合并的单元格填一个数据。
jf.getContentPane().add(new JScrollPane(new CTable(m, tm)));
jf.setDefaultCloseOperation(jf.EXIT_ON_CLOSE);
jf.setSize(500, 500);
jf.show();//jf.setVisibale(true)
  }
}