java - 根据列值更改 JTable 行的背景颜色

Question

嗨，我是 java jtable cellrendered 的新手。我正在寻找一种适用于我的程序的方法，但我没有运气找到它。 这是我的 Jtable

Employee ID   |   Name     |   Status    |   Position
  00565651        Roger       Active        Manager
  00565652        Gina        Active        Crew
  00565652        Alex        Inactive      Crew
  00565652        Seph        Active        Manager    

数据来自 MS Access 数据库，但我想更改状态列中值为“非 Activity ”的行的背景/前景。我在互联网上找到了很多例子，但所有这些在我的程序中都是不可能的。有人能帮我吗？ 这是我的模型

String[] columnNames = {"Employee ID","Name", "Status", "Position"};
DefaultTableModel model = new DefaultTableModel(columnNames, 0);

这是创建表以及从数据库获取数据的方式

public MyList(){//my constructor
    frame();
    loadListFromDB();
}
public void frame(){//
   //codes for frame setsize,titles etc...
   tblList = new JTable();
   tblList.getTableHeader().setPreferredSize(new Dimension(100, 40));
   tblList.getTableHeader().setFont(new Font("SansSerif", Font.BOLD, 25));
   tblList.setAutoCreateRowSorter(true);
   tblList.setModel(model);
   scrollPane.setViewportView(tblList);
   loadListFromDB();

}
public void loadListFromDB(){
   String sql = "SELECT emp_id,lname,fname,positional_status from tblEmployee";
    try{
        PreparedStatement ps = conn.prepareStatement(sql);
        ResultSet rs = ps.executeQuery();
        while (rs.next()){
            Vector row = new Vector();
            for (int i = 1; i <= 4; i++){
                row.addElement( rs.getObject(i) );
            }
            model.addRow(row);
        }
    }catch(Exception err){
        //for error code
    }
}

我该如何以这种方式添加表格？谁能给出简单的例子来改变行的颜色？预先感谢..我的程序停在这个问题上。

Answer 1

"i want to change the background/foreground of the rows which has a value of "inactive" in status column"

这实际上只是从表/模型中获取值的问题。如果该行的状态为非 Activity 状态，则为该行中的每个单元格设置背景/前景。由于渲染器是为每个单元格渲染的，因此基本上您需要获取 [row][statusColumn] 的值，这将是每行的状态值。类似的东西

table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer(){
    @Override
    public Component getTableCellRendererComponent(JTable table,
            Object value, boolean isSelected, boolean hasFocus, int row, int col) {

        super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, col);

        String status = (String)table.getModel().getValueAt(row, STATUS_COL);
        if ("active".equals(status)) {
            setBackground(Color.BLACK);
            setForeground(Color.WHITE);
        } else {
            setBackground(table.getBackground());
            setForeground(table.getForeground());
        }       
        return this;
    }   
});

这是一个简单的例子

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;

import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

public class TableRowDemo {

    private static final int STATUS_COL = 1;

    private static JTable getTable() {
        final String[] cols = {"col 1", "status", "col 3"};
        final String[][] data = {
                {"data", "active", "data"},
                {"data", "inactive", "data"},
                {"data", "inactive", "data"},
                {"data", "active", "data"}
        };
        DefaultTableModel model = new DefaultTableModel(data, cols);
        return new JTable(model) {
            @Override
            public Dimension getPreferredScrollableViewportSize() {
                return new Dimension(350, 150);
            }
        };
    }

    private static JTable getNewRenderedTable(final JTable table) {
        table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer(){
            @Override
            public Component getTableCellRendererComponent(JTable table,
                    Object value, boolean isSelected, boolean hasFocus, int row, int col) {
                super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, col);
                String status = (String)table.getModel().getValueAt(row, STATUS_COL);
                if ("active".equals(status)) {
                    setBackground(Color.BLACK);
                    setForeground(Color.WHITE);
                } else {
                    setBackground(table.getBackground());
                    setForeground(table.getForeground());
                }       
                return this;
            }   
        });
        return table;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                JOptionPane.showMessageDialog(null, new JScrollPane(getNewRenderedTable(getTable())));
            }
        });
    }
}

另一个选项是 @Override 表的 prepareRenderer 。它会给你相同的结果。

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;

import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;

public class TableRowDemo {

    private static final int STATUS_COL = 1;

    private static JTable getTable() {
        final String[] cols = {"col 1", "status", "col 3"};
        final String[][] data = {
                {"data", "active", "data"},
                {"data", "inactive", "data"},
                {"data", "inactive", "data"},
                {"data", "active", "data"}
        };
        DefaultTableModel model = new DefaultTableModel(data, cols);
        return new JTable(model) {
            @Override
            public Dimension getPreferredScrollableViewportSize() {
                return new Dimension(350, 150);
            }
            @Override
            public Component prepareRenderer(TableCellRenderer renderer, int row, int col) {
                Component c = super.prepareRenderer(renderer, row, col);
                String status = (String)getValueAt(row, STATUS_COL);
                if ("active".equals(status)) {
                    c.setBackground(Color.BLACK);
                    c.setForeground(Color.WHITE);
                } else {
                    c.setBackground(super.getBackground());
                    c.setForeground(super.getForeground());
                }
                return c;
            }
        };
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                JOptionPane.showMessageDialog(null, new JScrollPane(getTable()));
            }
        });
    }
}