一起使用TableCellRenderer和getColumnClass [英] Using TableCellRenderer and getColumnClass together

问题描述

当我将getcolumn类添加到我的abstracttablemodel时，我无法使用我的自定义TableCellRenderer来设置背景颜色。 （我用它来排序，对齐数字列）

when i add getcolumn class to my abstracttablemodel, i couldnt use my custom TableCellRenderer to set background color. (i use this for sorting,alignment numeric columns)

public Class getColumnClass(int columnIndex) {
        Object o = getValueAt(0, columnIndex);
        if (o == null) {
          return Object.class;
        } else {
          return o.getClass();
        }
      }

这是我的代码。

import java.awt.*;
import java.text.DecimalFormat;
import javax.swing.*;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.table.*;

public class DemoRenderer extends JFrame {

    public static void main( String[] args ) {
        DemoRenderer frame = new DemoRenderer();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible( true );
    }

    public DemoRenderer() {

                JTable table = new JTable();
                table.setModel(new MyTablemodel());
                table.setDefaultRenderer(Object.class, new MyCustomTableCellRenderer());

                // Tell the table what to use to render our column of doubles

                table.repaint();
                //table.getColumnModel().getColumn(1).setCellRenderer(new DecimalFormatRenderer() );                
        getContentPane().add(new JScrollPane(table));
    }

}

/**
         Here is our class to handle the formatting of the double values
         */

class MyCustomTableCellRenderer extends DefaultTableCellRenderer{

    private static final DecimalFormat formatter = new DecimalFormat( "#0.00" );

    public Component getTableCellRendererComponent (JTable table, 
             Object obj, boolean isSelected, boolean hasFocus, int row, int column) {

        if(column==1) obj = formatter.format((Number)obj);        
        Component cell = super.getTableCellRendererComponent(
            table, obj, isSelected, hasFocus, row, column);
    if (isSelected) {
    cell.setBackground(Color.green);
    } 
    else {
    if (row % 2 == 0) {
    cell.setBackground(Color.cyan);
    }
    else {
    cell.setBackground(Color.lightGray);
    }
    }    
    return cell; 
    }
}

class MyTablemodel extends AbstractTableModel{

    Object[] columnNames = { "A", "B", "C" };
    Object[][] data = {
    { "1abc", new Double(850.503), 53 },
    { "2def", new Double(36.23254), 6 },
    { "3ghi", new Double( 8.3 ), 7 },
    { "4jkl", new Double( 246.0943 ), 23 }};

    @Override
    public int getRowCount() {
        return data.length;
    }

    @Override
    public int getColumnCount() {
        return columnNames.length;
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        return data[rowIndex][columnIndex];
    }


    public Class getColumnClass(int columnIndex) {
        Object o = getValueAt(0, columnIndex);
        if (o == null) {
          return Object.class;
        } else {
          return o.getClass();
        }
      }

}

谢谢非常适合你的意见。

thank you very much for your opinions.

推荐答案

使用 TableColumn＃setCellRenderer（）为每列绘制单个值。

Use TableColumn#setCellRenderer() to draw individual values for each column.

只需在代码中添加以下行

Just add below lines in your code

MyCustomTableCellRenderer cellRenderer = new MyCustomTableCellRenderer();
for (int i = 0; i < table.getColumnCount(); i++) {
    table.getColumnModel().getColumn(i).setCellRenderer(cellRenderer);
}

而不是

table.setDefaultRenderer(Object.class, new MyCustomTableCellRenderer());

您的问题将得到解决。

注意：您正在使用将在单元格上应用的 DefaultTableCellRenderer ，因此使用 setCellRenderer（）而不是 setDefaultRenderer（）。

Note: You are using DefaultTableCellRenderer that will apply on cell hence use setCellRenderer() instead of setDefaultRenderer().

screenshot :(选择一行）

screenshot: (one row is selected)

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