更改单元格颜色而不更改其他单元格中的颜色（Jtable） [英] Changing Cell Color without changing color in other cells (Jtable)
本文介绍了更改单元格颜色而不更改其他单元格中的颜色（Jtable）的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
所以说，我们有一个JTable有31列和10行。
并且我想将第2列4行的颜色更改为红色。
在我改变另一个单元格颜色，而不会失去我以前的单元格的颜色。
我尝试以下没有成功：
public class CellR extends DefaultTableCellRenderer {
public Component getTableCellRendererComponent（JTable table，
Object value，boolean isSelected， boolean hasFocus，
int row，int column）{
setForeground（Color.white）;
if（row == TestHotel.v.getRow（）&& amp; column == TestHotel.v.getCol（））{
//仅适用于特定单元格
// c。 setFont（/ * special font * /）;
//你可能想在这里也选择isSelected
setForeground（Color.BLACK）;
setBackground（Color.RED）;
}
return this;
}
如果我第一次调用渲染器，
解决方案
表格和列表中的单元格渲染器类似于邮票。 一个组件用于绘制全部单元格。另请参阅概念：编辑者和呈现者。如果要保留有关突出显示单元格的信息，您必须以某种方式存储它们。
一个示例（根据评论扩展）：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
public class CellRendererTest
{
public static void main（String [] args）
{
SwingUtilities.invokeLater（new Runnable b {
@Override
public void run（）
{
createAndShowGUI（）;
}
}
}
private static void createAndShowGUI（）
{
JFrame f = new JFrame（）;
f.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
String [] columnNames = {
名字，姓氏，运动};
Object [] [] data = {
{Kathy，Smith，Snowboarding}，
{John，Doe，Rowing}，
{Sue，Black，Knitting}，
{Jane，White，Speed reading}，
{Joe，Brown }
};
final JTable table = new JTable（data，columnNames）;
final ColoringCellRenderer cellRenderer = new ColoringCellRenderer（）;
TableColumnModel columnModel = table.getColumnModel（）;
int cc = columnModel.getColumnCount（）;
for（int c = 0; c
TableColumn column = columnModel.getColumn（c）;
column.setCellRenderer（cellRenderer）;
}
JScrollPane scrollPane = new JScrollPane（table）;
f.getContentPane（）。setLayout（new BorderLayout（））;
f.getContentPane（）。add（scrollPane，BorderLayout.CENTER）;
JButton addRandomColorButton = new JButton（Add random color）;
addRandomColorButton.addActionListener（new ActionListener（）
{
private随机随机= new随机（0）;
@Override
public void actionPerformed（ActionEvent e）
{
int rows = table.getRowCount（）;
int cols = table.getColumnCount（）;
int row = random.nextInt（rows）;
int col = random.nextInt（cols）;
int r = random.nextInt（255）;
int g = random.nextInt（255）;
int b = random.nextInt（255）;
cellRenderer.setCellColor（row，col，new Color（r，g，b））;
table.repaint（）;
}
}
f.getContentPane（）。add（addRandomColorButton，BorderLayout.SOUTH）;
f.pack（）;
f.setLocationRelativeTo（null）;
f.setVisible（true）;
}
}
class ColoringCellRenderer extends DefaultTableCellRenderer
{
private final Map< Point，Color> cellColors = new HashMap< Point，Color>（）;
void setCellColor（int r，int c，Color color）
{
if（color == null）
{
cellColors.remove Point（r，c））;
}
else
{
cellColors.put（new Point（r，c），color）;
}
}
private color getCellColor（int r，int c）
{
颜色color = cellColors.get ））;
if（color == null）
{
return Color.WHITE;
}
return color;
}
@Override
public Component getTableCellRendererComponent（JTable table，Object value，
boolean isSelected，boolean hasFocus，int row，int column）
{
super.getTableCellRendererComponent（
table，value，isSelected，hasFocus，row，column）;
color color = getCellColor（row，column）;
setBackground（color）;
return this;
}
}
编辑：剩下的部分是从原来的答案，只使用一个单元格的颜色。上面的新一个是更完整的（更强大，因为它可以 单色渲染器），但我将这里留下这里的完整性
这可以通过像这样的渲染器来实现：
class ColoringCellRenderer extends DefaultTableCellRenderer
{
private final Set< Point> highlightCells = new HashSet< Point>（）;
void setHighlighted（int r，int c，boolean highlighted）
{
if（highlight）
{
highlightCells.add（new Point ，C））;
}
else
{
highlightedCells.remove（new Point（r，c））;
}
}
private boolean isHighlighted（int r，int c）
{
return highlightCells.contains（new Point（r，c）） ;
}
public Component getTableCellRendererComponent（JTable table，Object value，
boolean isSelected，boolean hasFocus，int row，int column）
{
if（isHighlighted（row，column））
{
setForeground（Color.BLACK）;
setBackground（Color.RED）;
}
else
{
setForeground（Color.BLACK）;
setBackground（Color.WHITE）;
}
return this;
}
}
然后，您可以创建此渲染器的实例，添加或删除要突出显示的单元格：
ColoringCellRenderer r = new ColoringCellRenderer
//将renderer分配给表...
...
//稍后突出显示单元格：
r.setHighlighted（4,2，true）;
r.setHighlighted（6,1，true）;
r.setHighlighted（1,5，false）;
...
如果您想要您可以用映射特定点的映射替换 Set c $ c>（表示单元格的行/列）到颜色对象。
So say that we have a JTable with 31 columns and 10 rows. And I want to change the color of the 2 Column 4 row to red. And after I do that change another cell color without loosing the color of my previous cell.
I have tried the following without success:
public class CellR extends DefaultTableCellRenderer {
public Component getTableCellRendererComponent(JTable table,
Object value, boolean isSelected, boolean hasFocus,
int row, int column) {
setForeground(Color.white);
if(row == TestHotel.v.getRow() && column == TestHotel.v.getCol()){
// Only for specific cell
// c.setFont(/* special font*/);
// you may want to address isSelected here too
setForeground(Color.BLACK);
setBackground(Color.RED);
}
return this;
}
If I call the renderer the first time it is working... But if I then want to change another cell color I am loosing the first one.
解决方案
The cell renderers in tables and lists are used like a "stamp". One component is used for painting all the cells. Also see Concepts: Editors and Renderers. If you want to retain the information about the "highlighted" cells, you somehow have to store them.
An example (extended based on the comments) :
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
public class CellRendererTest
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
String[] columnNames = {
"First Name", "Last Name", "Sport" };
Object[][] data = {
{"Kathy", "Smith", "Snowboarding" },
{"John", "Doe", "Rowing" },
{"Sue", "Black", "Knitting"},
{"Jane", "White", "Speed reading"},
{"Joe", "Brown", "Pool"}
};
final JTable table = new JTable(data, columnNames);
final ColoringCellRenderer cellRenderer = new ColoringCellRenderer();
TableColumnModel columnModel = table.getColumnModel();
int cc = columnModel.getColumnCount();
for (int c=0; c<cc; c++)
{
TableColumn column = columnModel.getColumn(c);
column.setCellRenderer(cellRenderer);
}
JScrollPane scrollPane = new JScrollPane(table);
f.getContentPane().setLayout(new BorderLayout());
f.getContentPane().add(scrollPane, BorderLayout.CENTER);
JButton addRandomColorButton = new JButton("Add random color");
addRandomColorButton.addActionListener(new ActionListener()
{
private Random random = new Random(0);
@Override
public void actionPerformed(ActionEvent e)
{
int rows = table.getRowCount();
int cols = table.getColumnCount();
int row = random.nextInt(rows);
int col = random.nextInt(cols);
int r = random.nextInt(255);
int g = random.nextInt(255);
int b = random.nextInt(255);
cellRenderer.setCellColor(row, col, new Color(r,g,b));
table.repaint();
}
});
f.getContentPane().add(addRandomColorButton, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}
class ColoringCellRenderer extends DefaultTableCellRenderer
{
private final Map<Point, Color> cellColors = new HashMap<Point, Color>();
void setCellColor(int r, int c, Color color)
{
if (color == null)
{
cellColors.remove(new Point(r,c));
}
else
{
cellColors.put(new Point(r,c), color);
}
}
private Color getCellColor(int r, int c)
{
Color color = cellColors.get(new Point(r,c));
if (color == null)
{
return Color.WHITE;
}
return color;
}
@Override
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus, int row, int column)
{
super.getTableCellRendererComponent(
table, value, isSelected, hasFocus, row, column);
Color color = getCellColor(row, column);
setBackground(color);
return this;
}
}
EDIT: The remaining part was from the original answer, using only a single cell color. The new one above is more complete (and more powerful, because it can emulate the single-color renderer), but I'll leave this here for completeness
This could be achieved with a renderer like this one:
class ColoringCellRenderer extends DefaultTableCellRenderer
{
private final Set<Point> highlightedCells = new HashSet<Point>();
void setHighlighted(int r, int c, boolean highlighted)
{
if (highlighted)
{
highlightedCells.add(new Point(r,c));
}
else
{
highlightedCells.remove(new Point(r,c));
}
}
private boolean isHighlighted(int r, int c)
{
return highlightedCells.contains(new Point(r,c));
}
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus, int row, int column)
{
if (isHighlighted(row, column))
{
setForeground(Color.BLACK);
setBackground(Color.RED);
}
else
{
setForeground(Color.BLACK);
setBackground(Color.WHITE);
}
return this;
}
}
You can then create an instance of this renderer, and add or remove cells to be highlighted:
ColoringCellRenderer r = new ColoringCellRenderer();
// Assign renderer to table...
...
// Later, highlight cells:
r.setHighlighted(4,2,true);
r.setHighlighted(6,1,true);
r.setHighlighted(1,5,false);
...
If you want different colors for the cells, you could replace the Set with a Map that maps a particular Point (representing the row/column of the cell) to a Color object.
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