动态更改JTable单元格的颜色 [英] Changing the color of a JTable cell DYNAMICALLY

问题描述

我想知道如何在没有用户任何响应的情况下更改表格中单元格的背景颜色. 例如，如果我的变量之一由于某些不相关的方法调用而发生变化，那么我希望将其反映在表中. 例如，一个方法更改了我用来初始化表的数组的值，但是用户却没有手，例如说值的经过时间改变.因此，如何将其反映在我的桌子上，或者有什么方法可以手动调用TableCellRenderer

I would like to know how do i change the background color of a cell in a Table without any response from users. For example, if there is a change in one of my variables due to some unrelated method calls, which I would like for to be reflected in my table. Example, a method changes a value of my array that I used to initialize my table, however the user had no hand in it, like say a elapsed time change in value. So how do I reflect it on my table, or is there any way I could manually call the TableCellRenderer

带有代码段的更新问题，此处

updated question with code snippets here

推荐答案

建议使用自定义单元格渲染器:

As advised use a custom cell renderer:

import java.awt.Color;
import java.awt.Component;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableModel;

public class CellRenderDemo {

    private static final int MAX =120;
    private static Object[] columnName = {"Item", "Value"};
    private static Object[][] data = {{"Value A", 12}, {"Value B", 34},  {"Value C", 66}};
    private final JTable table;

    CellRenderDemo() {
        table = new JTable(data, columnName);
        table.getColumnModel().getColumn(1).setCellRenderer(new CustomRenderer());//use custom cell rendered for col 1
    }

    void randomizeData(){
        Random rnd = new Random();
        TableModel model = table.getModel();
        new Timer(1000, e->{
            model.setValueAt(rnd.nextInt(MAX+1), rnd.nextInt(model.getRowCount()), 1);
        }).start();
    }

    JTable getTable() {
        return table;
    }

    static class CustomRenderer extends DefaultTableCellRenderer {

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus,
                int row, int column)   {
            Component cellComponent = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);

            int cellValue = (int)value;
            if(cellValue <= MAX / 3){ //change color based on value 
                cellComponent.setBackground(Color.PINK);
            } else if ( cellValue > 2*MAX / 3){
                cellComponent.setBackground(Color.CYAN);
            } else {
                cellComponent.setBackground(Color.YELLOW);
            }
            return cellComponent;
        }
    }

    public static void main(String[] args) {
        Runnable r = () -> {
            JFrame frame = new JFrame();
            CellRenderDemo cd = new CellRenderDemo();
            frame.add(new JScrollPane(cd.getTable()));
            frame.pack();
            cd.randomizeData();
            frame.setVisible(true);
        };
        SwingUtilities.invokeLater(r);
    }
}

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