【Java】高级Swing——JTable

tech2022-07-16  156

相比JList,JTable显然要复杂很多。JTabel同样继承了java一贯的设计风格,将数据模型与表格的绘制分离。即有默认的样式,也提供了很多接口。这不仅使Java的表格设计思路清晰,而且几乎所有的个性化需要也可以得到满足。

缺点是:Java库中封装了过多的方法,为了使其尽可能通俗易懂,方法名和常量名非常长,这让Java代码看起来十分啰嗦,并不优美。但这在强大的IDE中可以用代码提示功能解决。

1.根据构造方法创建JTabel;可以传表的内容(二位数组),和表头(一维数组) 下面是我校的小图丁志愿者录取工作的名单表,名字瞎掰的。

class JTabelFrame extends JFrame { private String[] libVol= {"姓名","学号","联系方式","志愿楼层","时间段"}; private Object[][] text= { //名字纯属瞎掰 {"楚寒冰", "07190221" ,"18602511184", "二东,二西,七西,七东" ,"周六1,周六3,周日1,周三3"}, {"云天明", "12180243","18602511185","二东,二西,七东,七西","周二3,周四3,周日3"}, {"陈欣"," 05181343"," 18602511211"," 五东、五西、四东、四西、三东、三西 ","周一1、周二3、周四3"}, {"郑语嫣"," 25190133"," 18602511228"," 二东,二西,七东,七西"," 周二2、周五2"} {"何碧","010223","18952249826","二东,七西""周二3,周六2"} }; public JTabelFrame(String title) { super(title); setDefaultCloseOperation(EXIT_ON_CLOSE); //应用JTable的构造方法JTabel(Object[][],Object[]); * JTable table=new JTable(text,libVol); //设置列排列器,点击列头可对列排序 tabel.setAutoCreateRowSorter(true); JPanel panel=new JPanel(); panel.add(new JScrollPane(table)); add(panel,BorderLayout.CENTER); pack(); } }

2.定制数据模型,单元格渲染器 与JList一样,Java支持自定义单元格渲染器和数据模型。在数据模型中可对单元格是否可编辑进行重写,如

public boolean isCellEditable(int r,int c) { return c==0||c==1||c==2||c==3; }

单元格渲染器和JList过程一至,实现getTableCellRendererComponent方法后返回Component对象,用paintComponent方法绘制单元格,这里用到常用的字符串测量技术把字符串放在合适的位置 另外,用单元格编辑器还可以对单元格进行更深层次的操作,比如添加组合框,事件等,这比较复杂,可以参考API文档和《Java核心技术》。 给一个例子:

package JTable; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Component; import java.awt.EventQueue; import java.awt.Font; import java.awt.FontMetrics; import java.awt.Graphics; import java.sql.Date; import javax.swing.AbstractCellEditor; import javax.swing.DefaultCellEditor; import javax.swing.ImageIcon; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.UIManager; import javax.swing.table.AbstractTableModel; import javax.swing.table.DefaultTableCellRenderer; import javax.swing.table.DefaultTableModel; import javax.swing.table.TableCellRenderer; import javax.swing.table.TableModel; public class IdolTabel { public static void main(String[] args) { EventQueue.invokeLater(()->{ IdolTableFrame frame=new IdolTableFrame("idol"); frame.setVisible(true); }); } } class IdolTableFrame extends JFrame { private static final int DEFDAULT_WIDTH=700; private static final int DEFDAULT_HEIGHT=500; private JTable table; public IdolTableFrame(String title) { super(title); setSize(DEFDAULT_WIDTH, DEFDAULT_HEIGHT); TableModel model=new IdolModel(); //添加数据模型 table=new JTable(model); //设置默认排序器,点击表头可排序 table.setAutoCreateRowSorter(true); table.setRowHeight(240); table.setRowSelectionAllowed(false); //添加单元格渲染器,对String类单元格渲染 table.setDefaultRenderer(String.class, new MyRenderer()); //对图片框单独设置 JComboBox<Integer> comb=new JComboBox<>(); for(int i=1;i<=40;i++) comb.addItem(i); table.getColumnModel().getColumn(2).setCellEditor(new DefaultCellEditor(comb)); table.getColumnModel().getColumn(4).setMinWidth(150); table.getColumnModel().getColumn(4).setMinWidth(200); add(new JScrollPane(table),BorderLayout.CENTER); } } class MyRenderer extends JPanel implements TableCellRenderer { private static Color background; private static String text; private Font font=new Font(Font.SANS_SERIF,Font.PLAIN,17); @Override public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) { this.text=(String) value; background=isSelected?new Color(64, 0, 64):column%2==1?new Color(255, 255, 225):Color.WHITE; if(hasFocus) { setBorder(UIManager.getBorder("Table.focusCellHighlightBorder")); }else setBorder(null); return this; } public void paintComponent(Graphics g) { g.setColor(background); g.fillRect(0, 0, getWidth(), getHeight()); g.setColor(new Color(165, 107, 77)); g.drawRect(0, 0, getWidth(), getHeight()); FontMetrics fm=g.getFontMetrics(font); g.setColor(Color.BLACK); g.drawString(text, (getWidth()-fm.stringWidth(text))/2, (getHeight()-fm.getHeight())/2); } } class IdolModel extends AbstractTableModel { private String[] colnumNames= {"姓名","国籍","年龄","出生日期","照片"}; private Object[][] cells= { {"白石麻衣","日本","22","1998.8.10",new ImageIcon(getClass().getResource("bsmy.jpg"))}, {"Emma Watson","英国","30","1990.4.15",new ImageIcon(getClass().getResource("emma.jfif"))}, {"文彩元","韩国","33","1986.11.13",new ImageIcon(getClass().getResource("wcy.jfif"))} }; @Override public int getRowCount() { return cells.length; } @Override public int getColumnCount() { return cells[0].length; } public String getColumnName(int c) { return colnumNames[c]; } @Override public Object getValueAt(int rowIndex, int columnIndex) { return cells[rowIndex][columnIndex]; } public Class<?> getColumnClass(int c) { return cells[0][c].getClass(); } public boolean isCellEditable(int r,int c) { return c==0||c==1||c==2||c==3; } }

图片如下:

Java的Swing组件功能十分强大,而且设计起来并不复杂,完成定制只需实现相应接口。

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